LPC1700CMSIS_Examples - These are the examples provided for [[/users/fran…

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These are the examples provided for [[/users/frank26080115/libraries/LPC1700CMSIS_Lib/]] Note, the entire "program" is not compilable!

EMAC/uIP/uip/uip.c@0:bf7b9fba3924, 2011-03-20 (annotated)

Committer:: frank26080115
Date:: Sun Mar 20 05:38:56 2011 +0000
Revision:: 0:bf7b9fba3924

Who changed what in which revision?

User	Revision	Line number	New contents of line
frank26080115	0:bf7b9fba3924	1	#define DEBUG_PRINTF(...) /printf(__VA_ARGS__)/
frank26080115	0:bf7b9fba3924	2	/** @addtogroup EMAC_uIP
frank26080115	0:bf7b9fba3924	3	* @{
frank26080115	0:bf7b9fba3924	4	*/
frank26080115	0:bf7b9fba3924	5
frank26080115	0:bf7b9fba3924	6	/**
frank26080115	0:bf7b9fba3924	7	* \defgroup uip The uIP TCP/IP stack
frank26080115	0:bf7b9fba3924	8	* @{
frank26080115	0:bf7b9fba3924	9	*
frank26080115	0:bf7b9fba3924	10	* uIP is an implementation of the TCP/IP protocol stack intended for
frank26080115	0:bf7b9fba3924	11	* small 8-bit and 16-bit microcontrollers.
frank26080115	0:bf7b9fba3924	12	*
frank26080115	0:bf7b9fba3924	13	* uIP provides the necessary protocols for Internet communication,
frank26080115	0:bf7b9fba3924	14	* with a very small code footprint and RAM requirements - the uIP
frank26080115	0:bf7b9fba3924	15	* code size is on the order of a few kilobytes and RAM usage is on
frank26080115	0:bf7b9fba3924	16	* the order of a few hundred bytes.
frank26080115	0:bf7b9fba3924	17	*/
frank26080115	0:bf7b9fba3924	18
frank26080115	0:bf7b9fba3924	19	/** @addtogroup EMAC_uIP
frank26080115	0:bf7b9fba3924	20	* @{
frank26080115	0:bf7b9fba3924	21	*/
frank26080115	0:bf7b9fba3924	22
frank26080115	0:bf7b9fba3924	23	/**
frank26080115	0:bf7b9fba3924	24	* \file
frank26080115	0:bf7b9fba3924	25	* The uIP TCP/IP stack code.
frank26080115	0:bf7b9fba3924	26	* \author Adam Dunkels <adam@dunkels.com>
frank26080115	0:bf7b9fba3924	27	*/
frank26080115	0:bf7b9fba3924	28
frank26080115	0:bf7b9fba3924	29	/*
frank26080115	0:bf7b9fba3924	30	* Copyright (c) 2001-2003, Adam Dunkels.
frank26080115	0:bf7b9fba3924	31	* All rights reserved.
frank26080115	0:bf7b9fba3924	32	*
frank26080115	0:bf7b9fba3924	33	* Redistribution and use in source and binary forms, with or without
frank26080115	0:bf7b9fba3924	34	* modification, are permitted provided that the following conditions
frank26080115	0:bf7b9fba3924	35	* are met:
frank26080115	0:bf7b9fba3924	36	* 1. Redistributions of source code must retain the above copyright
frank26080115	0:bf7b9fba3924	37	* notice, this list of conditions and the following disclaimer.
frank26080115	0:bf7b9fba3924	38	* 2. Redistributions in binary form must reproduce the above copyright
frank26080115	0:bf7b9fba3924	39	* notice, this list of conditions and the following disclaimer in the
frank26080115	0:bf7b9fba3924	40	* documentation and/or other materials provided with the distribution.
frank26080115	0:bf7b9fba3924	41	* 3. The name of the author may not be used to endorse or promote
frank26080115	0:bf7b9fba3924	42	* products derived from this software without specific prior
frank26080115	0:bf7b9fba3924	43	* written permission.
frank26080115	0:bf7b9fba3924	44	*
frank26080115	0:bf7b9fba3924	45	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
frank26080115	0:bf7b9fba3924	46	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
frank26080115	0:bf7b9fba3924	47	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
frank26080115	0:bf7b9fba3924	48	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
frank26080115	0:bf7b9fba3924	49	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
frank26080115	0:bf7b9fba3924	50	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
frank26080115	0:bf7b9fba3924	51	* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
frank26080115	0:bf7b9fba3924	52	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
frank26080115	0:bf7b9fba3924	53	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
frank26080115	0:bf7b9fba3924	54	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
frank26080115	0:bf7b9fba3924	55	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
frank26080115	0:bf7b9fba3924	56	*
frank26080115	0:bf7b9fba3924	57	* This file is part of the uIP TCP/IP stack.
frank26080115	0:bf7b9fba3924	58	*
frank26080115	0:bf7b9fba3924	59	* $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $
frank26080115	0:bf7b9fba3924	60	*
frank26080115	0:bf7b9fba3924	61	*/
frank26080115	0:bf7b9fba3924	62
frank26080115	0:bf7b9fba3924	63	/*
frank26080115	0:bf7b9fba3924	64	* uIP is a small implementation of the IP, UDP and TCP protocols (as
frank26080115	0:bf7b9fba3924	65	* well as some basic ICMP stuff). The implementation couples the IP,
frank26080115	0:bf7b9fba3924	66	* UDP, TCP and the application layers very tightly. To keep the size
frank26080115	0:bf7b9fba3924	67	* of the compiled code down, this code frequently uses the goto
frank26080115	0:bf7b9fba3924	68	* statement. While it would be possible to break the uip_process()
frank26080115	0:bf7b9fba3924	69	* function into many smaller functions, this would increase the code
frank26080115	0:bf7b9fba3924	70	* size because of the overhead of parameter passing and the fact that
frank26080115	0:bf7b9fba3924	71	* the optimier would not be as efficient.
frank26080115	0:bf7b9fba3924	72	*
frank26080115	0:bf7b9fba3924	73	* The principle is that we have a small buffer, called the uip_buf,
frank26080115	0:bf7b9fba3924	74	* in which the device driver puts an incoming packet. The TCP/IP
frank26080115	0:bf7b9fba3924	75	* stack parses the headers in the packet, and calls the
frank26080115	0:bf7b9fba3924	76	* application. If the remote host has sent data to the application,
frank26080115	0:bf7b9fba3924	77	* this data is present in the uip_buf and the application read the
frank26080115	0:bf7b9fba3924	78	* data from there. It is up to the application to put this data into
frank26080115	0:bf7b9fba3924	79	* a byte stream if needed. The application will not be fed with data
frank26080115	0:bf7b9fba3924	80	* that is out of sequence.
frank26080115	0:bf7b9fba3924	81	*
frank26080115	0:bf7b9fba3924	82	* If the application whishes to send data to the peer, it should put
frank26080115	0:bf7b9fba3924	83	* its data into the uip_buf. The uip_appdata pointer points to the
frank26080115	0:bf7b9fba3924	84	* first available byte. The TCP/IP stack will calculate the
frank26080115	0:bf7b9fba3924	85	* checksums, and fill in the necessary header fields and finally send
frank26080115	0:bf7b9fba3924	86	* the packet back to the peer.
frank26080115	0:bf7b9fba3924	87	*/
frank26080115	0:bf7b9fba3924	88
frank26080115	0:bf7b9fba3924	89	#include "uip.h"
frank26080115	0:bf7b9fba3924	90	#include "uipopt.h"
frank26080115	0:bf7b9fba3924	91	#include "uip_arch.h"
frank26080115	0:bf7b9fba3924	92
frank26080115	0:bf7b9fba3924	93	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	94	#include "uip-neighbor.h"
frank26080115	0:bf7b9fba3924	95	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	96
frank26080115	0:bf7b9fba3924	97	#include <string.h>
frank26080115	0:bf7b9fba3924	98
frank26080115	0:bf7b9fba3924	99	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	100	/* Variable definitions. */
frank26080115	0:bf7b9fba3924	101
frank26080115	0:bf7b9fba3924	102
frank26080115	0:bf7b9fba3924	103	/* The IP address of this host. If it is defined to be fixed (by
frank26080115	0:bf7b9fba3924	104	setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
frank26080115	0:bf7b9fba3924	105	here. Otherwise, the address */
frank26080115	0:bf7b9fba3924	106	#if UIP_FIXEDADDR > 0
frank26080115	0:bf7b9fba3924	107	const uip_ipaddr_t uip_hostaddr =
frank26080115	0:bf7b9fba3924	108	{HTONS((UIP_IPADDR0 << 8) \| UIP_IPADDR1),
frank26080115	0:bf7b9fba3924	109	HTONS((UIP_IPADDR2 << 8) \| UIP_IPADDR3)};
frank26080115	0:bf7b9fba3924	110	const uip_ipaddr_t uip_draddr =
frank26080115	0:bf7b9fba3924	111	{HTONS((UIP_DRIPADDR0 << 8) \| UIP_DRIPADDR1),
frank26080115	0:bf7b9fba3924	112	HTONS((UIP_DRIPADDR2 << 8) \| UIP_DRIPADDR3)};
frank26080115	0:bf7b9fba3924	113	const uip_ipaddr_t uip_netmask =
frank26080115	0:bf7b9fba3924	114	{HTONS((UIP_NETMASK0 << 8) \| UIP_NETMASK1),
frank26080115	0:bf7b9fba3924	115	HTONS((UIP_NETMASK2 << 8) \| UIP_NETMASK3)};
frank26080115	0:bf7b9fba3924	116	#else
frank26080115	0:bf7b9fba3924	117	uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
frank26080115	0:bf7b9fba3924	118	#endif /* UIP_FIXEDADDR */
frank26080115	0:bf7b9fba3924	119
frank26080115	0:bf7b9fba3924	120	static const uip_ipaddr_t all_ones_addr =
frank26080115	0:bf7b9fba3924	121	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	122	{0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
frank26080115	0:bf7b9fba3924	123	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	124	{0xffff,0xffff};
frank26080115	0:bf7b9fba3924	125	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	126	static const uip_ipaddr_t all_zeroes_addr =
frank26080115	0:bf7b9fba3924	127	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	128	{0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
frank26080115	0:bf7b9fba3924	129	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	130	{0x0000,0x0000};
frank26080115	0:bf7b9fba3924	131	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	132
frank26080115	0:bf7b9fba3924	133	#if UIP_FIXEDETHADDR
frank26080115	0:bf7b9fba3924	134	const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0,
frank26080115	0:bf7b9fba3924	135	UIP_ETHADDR1,
frank26080115	0:bf7b9fba3924	136	UIP_ETHADDR2,
frank26080115	0:bf7b9fba3924	137	UIP_ETHADDR3,
frank26080115	0:bf7b9fba3924	138	UIP_ETHADDR4,
frank26080115	0:bf7b9fba3924	139	UIP_ETHADDR5}};
frank26080115	0:bf7b9fba3924	140	#else
frank26080115	0:bf7b9fba3924	141	struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}};
frank26080115	0:bf7b9fba3924	142	#endif
frank26080115	0:bf7b9fba3924	143
frank26080115	0:bf7b9fba3924	144	#ifndef UIP_CONF_EXTERNAL_BUFFER
frank26080115	0:bf7b9fba3924	145
frank26080115	0:bf7b9fba3924	146	#if defined ( __CC_ARM )
frank26080115	0:bf7b9fba3924	147	u8_t __align(4) uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains incoming packets. */
frank26080115	0:bf7b9fba3924	148	#elif defined ( __ICCARM__ )
frank26080115	0:bf7b9fba3924	149	#pragma data_alignment=4
frank26080115	0:bf7b9fba3924	150	u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains incoming packets. */
frank26080115	0:bf7b9fba3924	151	#elif defined ( __GNUC__ )
frank26080115	0:bf7b9fba3924	152	u8_t __attribute__ ((aligned (4))) uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains incoming packets. */
frank26080115	0:bf7b9fba3924	153	#endif
frank26080115	0:bf7b9fba3924	154
frank26080115	0:bf7b9fba3924	155	/ALIGN_STRUCT_END/
frank26080115	0:bf7b9fba3924	156
frank26080115	0:bf7b9fba3924	157	#endif /* UIP_CONF_EXTERNAL_BUFFER */
frank26080115	0:bf7b9fba3924	158
frank26080115	0:bf7b9fba3924	159	void uip_appdata; / The uip_appdata pointer points to
frank26080115	0:bf7b9fba3924	160	application data. */
frank26080115	0:bf7b9fba3924	161	void uip_sappdata; / The uip_appdata pointer points to
frank26080115	0:bf7b9fba3924	162	the application data which is to
frank26080115	0:bf7b9fba3924	163	be sent. */
frank26080115	0:bf7b9fba3924	164	#if UIP_URGDATA > 0
frank26080115	0:bf7b9fba3924	165	void uip_urgdata; / The uip_urgdata pointer points to
frank26080115	0:bf7b9fba3924	166	urgent data (out-of-band data), if
frank26080115	0:bf7b9fba3924	167	present. */
frank26080115	0:bf7b9fba3924	168	u16_t uip_urglen, uip_surglen;
frank26080115	0:bf7b9fba3924	169	#endif /* UIP_URGDATA > 0 */
frank26080115	0:bf7b9fba3924	170
frank26080115	0:bf7b9fba3924	171	u16_t uip_len, uip_slen;
frank26080115	0:bf7b9fba3924	172	/* The uip_len is either 8 or 16 bits,
frank26080115	0:bf7b9fba3924	173	depending on the maximum packet
frank26080115	0:bf7b9fba3924	174	size. */
frank26080115	0:bf7b9fba3924	175
frank26080115	0:bf7b9fba3924	176	u8_t uip_flags; /* The uip_flags variable is used for
frank26080115	0:bf7b9fba3924	177	communication between the TCP/IP stack
frank26080115	0:bf7b9fba3924	178	and the application program. */
frank26080115	0:bf7b9fba3924	179	struct uip_conn uip_conn; / uip_conn always points to the current
frank26080115	0:bf7b9fba3924	180	connection. */
frank26080115	0:bf7b9fba3924	181
frank26080115	0:bf7b9fba3924	182	struct uip_conn uip_conns[UIP_CONNS];
frank26080115	0:bf7b9fba3924	183	/* The uip_conns array holds all TCP
frank26080115	0:bf7b9fba3924	184	connections. */
frank26080115	0:bf7b9fba3924	185	u16_t uip_listenports[UIP_LISTENPORTS];
frank26080115	0:bf7b9fba3924	186	/* The uip_listenports list all currently
frank26080115	0:bf7b9fba3924	187	listning ports. */
frank26080115	0:bf7b9fba3924	188	#if UIP_UDP
frank26080115	0:bf7b9fba3924	189	struct uip_udp_conn *uip_udp_conn;
frank26080115	0:bf7b9fba3924	190	struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
frank26080115	0:bf7b9fba3924	191	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	192
frank26080115	0:bf7b9fba3924	193	static u16_t ipid; /* Ths ipid variable is an increasing
frank26080115	0:bf7b9fba3924	194	number that is used for the IP ID
frank26080115	0:bf7b9fba3924	195	field. */
frank26080115	0:bf7b9fba3924	196
frank26080115	0:bf7b9fba3924	197	void uip_setipid(u16_t id) { ipid = id; }
frank26080115	0:bf7b9fba3924	198
frank26080115	0:bf7b9fba3924	199	static u8_t iss[4]; /* The iss variable is used for the TCP
frank26080115	0:bf7b9fba3924	200	initial sequence number. */
frank26080115	0:bf7b9fba3924	201
frank26080115	0:bf7b9fba3924	202	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	203	static u16_t lastport; /* Keeps track of the last port used for
frank26080115	0:bf7b9fba3924	204	a new connection. */
frank26080115	0:bf7b9fba3924	205	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	206
frank26080115	0:bf7b9fba3924	207	/* Temporary variables. */
frank26080115	0:bf7b9fba3924	208	u8_t uip_acc32[4];
frank26080115	0:bf7b9fba3924	209	static u8_t c, opt;
frank26080115	0:bf7b9fba3924	210	static u16_t tmp16;
frank26080115	0:bf7b9fba3924	211
frank26080115	0:bf7b9fba3924	212	/* Structures and definitions. */
frank26080115	0:bf7b9fba3924	213	#define TCP_FIN 0x01
frank26080115	0:bf7b9fba3924	214	#define TCP_SYN 0x02
frank26080115	0:bf7b9fba3924	215	#define TCP_RST 0x04
frank26080115	0:bf7b9fba3924	216	#define TCP_PSH 0x08
frank26080115	0:bf7b9fba3924	217	#define TCP_ACK 0x10
frank26080115	0:bf7b9fba3924	218	#define TCP_URG 0x20
frank26080115	0:bf7b9fba3924	219	#define TCP_CTL 0x3f
frank26080115	0:bf7b9fba3924	220
frank26080115	0:bf7b9fba3924	221	#define TCP_OPT_END 0 /* End of TCP options list */
frank26080115	0:bf7b9fba3924	222	#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
frank26080115	0:bf7b9fba3924	223	#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
frank26080115	0:bf7b9fba3924	224
frank26080115	0:bf7b9fba3924	225	#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
frank26080115	0:bf7b9fba3924	226
frank26080115	0:bf7b9fba3924	227	#define ICMP_ECHO_REPLY 0
frank26080115	0:bf7b9fba3924	228	#define ICMP_ECHO 8
frank26080115	0:bf7b9fba3924	229
frank26080115	0:bf7b9fba3924	230	#define ICMP6_ECHO_REPLY 129
frank26080115	0:bf7b9fba3924	231	#define ICMP6_ECHO 128
frank26080115	0:bf7b9fba3924	232	#define ICMP6_NEIGHBOR_SOLICITATION 135
frank26080115	0:bf7b9fba3924	233	#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
frank26080115	0:bf7b9fba3924	234
frank26080115	0:bf7b9fba3924	235	#define ICMP6_FLAG_S (1 << 6)
frank26080115	0:bf7b9fba3924	236
frank26080115	0:bf7b9fba3924	237	#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
frank26080115	0:bf7b9fba3924	238	#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
frank26080115	0:bf7b9fba3924	239
frank26080115	0:bf7b9fba3924	240
frank26080115	0:bf7b9fba3924	241	/* Macros. */
frank26080115	0:bf7b9fba3924	242	#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
frank26080115	0:bf7b9fba3924	243	#define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
frank26080115	0:bf7b9fba3924	244	#define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
frank26080115	0:bf7b9fba3924	245	#define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
frank26080115	0:bf7b9fba3924	246
frank26080115	0:bf7b9fba3924	247
frank26080115	0:bf7b9fba3924	248	#if UIP_STATISTICS == 1
frank26080115	0:bf7b9fba3924	249	struct uip_stats uip_stat;
frank26080115	0:bf7b9fba3924	250	#define UIP_STAT(s) s
frank26080115	0:bf7b9fba3924	251	#else
frank26080115	0:bf7b9fba3924	252	#define UIP_STAT(s)
frank26080115	0:bf7b9fba3924	253	#endif /* UIP_STATISTICS == 1 */
frank26080115	0:bf7b9fba3924	254
frank26080115	0:bf7b9fba3924	255	#if UIP_LOGGING == 1
frank26080115	0:bf7b9fba3924	256	#include <stdio.h>
frank26080115	0:bf7b9fba3924	257	void uip_log(char *msg);
frank26080115	0:bf7b9fba3924	258	#define UIP_LOG(m) uip_log(m)
frank26080115	0:bf7b9fba3924	259	#else
frank26080115	0:bf7b9fba3924	260	#define UIP_LOG(m)
frank26080115	0:bf7b9fba3924	261	#endif /* UIP_LOGGING == 1 */
frank26080115	0:bf7b9fba3924	262
frank26080115	0:bf7b9fba3924	263	#if ! UIP_ARCH_ADD32
frank26080115	0:bf7b9fba3924	264	void
frank26080115	0:bf7b9fba3924	265	uip_add32(u8_t *op32, u16_t op16)
frank26080115	0:bf7b9fba3924	266	{
frank26080115	0:bf7b9fba3924	267	uip_acc32[3] = op32[3] + (op16 & 0xff);
frank26080115	0:bf7b9fba3924	268	uip_acc32[2] = op32[2] + (op16 >> 8);
frank26080115	0:bf7b9fba3924	269	uip_acc32[1] = op32[1];
frank26080115	0:bf7b9fba3924	270	uip_acc32[0] = op32[0];
frank26080115	0:bf7b9fba3924	271
frank26080115	0:bf7b9fba3924	272	if(uip_acc32[2] < (op16 >> 8)) {
frank26080115	0:bf7b9fba3924	273	++uip_acc32[1];
frank26080115	0:bf7b9fba3924	274	if(uip_acc32[1] == 0) {
frank26080115	0:bf7b9fba3924	275	++uip_acc32[0];
frank26080115	0:bf7b9fba3924	276	}
frank26080115	0:bf7b9fba3924	277	}
frank26080115	0:bf7b9fba3924	278
frank26080115	0:bf7b9fba3924	279
frank26080115	0:bf7b9fba3924	280	if(uip_acc32[3] < (op16 & 0xff)) {
frank26080115	0:bf7b9fba3924	281	++uip_acc32[2];
frank26080115	0:bf7b9fba3924	282	if(uip_acc32[2] == 0) {
frank26080115	0:bf7b9fba3924	283	++uip_acc32[1];
frank26080115	0:bf7b9fba3924	284	if(uip_acc32[1] == 0) {
frank26080115	0:bf7b9fba3924	285	++uip_acc32[0];
frank26080115	0:bf7b9fba3924	286	}
frank26080115	0:bf7b9fba3924	287	}
frank26080115	0:bf7b9fba3924	288	}
frank26080115	0:bf7b9fba3924	289	}
frank26080115	0:bf7b9fba3924	290
frank26080115	0:bf7b9fba3924	291	#endif /* UIP_ARCH_ADD32 */
frank26080115	0:bf7b9fba3924	292
frank26080115	0:bf7b9fba3924	293	#if ! UIP_ARCH_CHKSUM
frank26080115	0:bf7b9fba3924	294	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	295	static u16_t
frank26080115	0:bf7b9fba3924	296	chksum(u16_t sum, const u8_t *data, u16_t len)
frank26080115	0:bf7b9fba3924	297	{
frank26080115	0:bf7b9fba3924	298	u16_t t;
frank26080115	0:bf7b9fba3924	299	const u8_t *dataptr;
frank26080115	0:bf7b9fba3924	300	const u8_t *last_byte;
frank26080115	0:bf7b9fba3924	301
frank26080115	0:bf7b9fba3924	302	dataptr = data;
frank26080115	0:bf7b9fba3924	303	last_byte = data + len - 1;
frank26080115	0:bf7b9fba3924	304
frank26080115	0:bf7b9fba3924	305	while(dataptr < last_byte) { /* At least two more bytes */
frank26080115	0:bf7b9fba3924	306	t = (dataptr[0] << 8) + dataptr[1];
frank26080115	0:bf7b9fba3924	307	sum += t;
frank26080115	0:bf7b9fba3924	308	if(sum < t) {
frank26080115	0:bf7b9fba3924	309	sum++; /* carry */
frank26080115	0:bf7b9fba3924	310	}
frank26080115	0:bf7b9fba3924	311	dataptr += 2;
frank26080115	0:bf7b9fba3924	312	}
frank26080115	0:bf7b9fba3924	313
frank26080115	0:bf7b9fba3924	314	if(dataptr == last_byte) {
frank26080115	0:bf7b9fba3924	315	t = (dataptr[0] << 8) + 0;
frank26080115	0:bf7b9fba3924	316	sum += t;
frank26080115	0:bf7b9fba3924	317	if(sum < t) {
frank26080115	0:bf7b9fba3924	318	sum++; /* carry */
frank26080115	0:bf7b9fba3924	319	}
frank26080115	0:bf7b9fba3924	320	}
frank26080115	0:bf7b9fba3924	321
frank26080115	0:bf7b9fba3924	322	/* Return sum in host byte order. */
frank26080115	0:bf7b9fba3924	323	return sum;
frank26080115	0:bf7b9fba3924	324	}
frank26080115	0:bf7b9fba3924	325	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	326	u16_t
frank26080115	0:bf7b9fba3924	327	uip_chksum(u16_t *data, u16_t len)
frank26080115	0:bf7b9fba3924	328	{
frank26080115	0:bf7b9fba3924	329	return htons(chksum(0, (u8_t *)data, len));
frank26080115	0:bf7b9fba3924	330	}
frank26080115	0:bf7b9fba3924	331	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	332	#ifndef UIP_ARCH_IPCHKSUM
frank26080115	0:bf7b9fba3924	333	u16_t
frank26080115	0:bf7b9fba3924	334	uip_ipchksum(void)
frank26080115	0:bf7b9fba3924	335	{
frank26080115	0:bf7b9fba3924	336	u16_t sum;
frank26080115	0:bf7b9fba3924	337
frank26080115	0:bf7b9fba3924	338	sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
frank26080115	0:bf7b9fba3924	339	DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
frank26080115	0:bf7b9fba3924	340	return (sum == 0) ? 0xffff : htons(sum);
frank26080115	0:bf7b9fba3924	341	}
frank26080115	0:bf7b9fba3924	342	#endif
frank26080115	0:bf7b9fba3924	343	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	344	static u16_t
frank26080115	0:bf7b9fba3924	345	upper_layer_chksum(u8_t proto)
frank26080115	0:bf7b9fba3924	346	{
frank26080115	0:bf7b9fba3924	347	u16_t upper_layer_len;
frank26080115	0:bf7b9fba3924	348	u16_t sum;
frank26080115	0:bf7b9fba3924	349
frank26080115	0:bf7b9fba3924	350	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	351	upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]);
frank26080115	0:bf7b9fba3924	352	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	353	upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
frank26080115	0:bf7b9fba3924	354	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	355
frank26080115	0:bf7b9fba3924	356	/* First sum pseudoheader. */
frank26080115	0:bf7b9fba3924	357
frank26080115	0:bf7b9fba3924	358	/* IP protocol and length fields. This addition cannot carry. */
frank26080115	0:bf7b9fba3924	359	sum = upper_layer_len + proto;
frank26080115	0:bf7b9fba3924	360	/* Sum IP source and destination addresses. */
frank26080115	0:bf7b9fba3924	361	sum = chksum(sum, (u8_t )&BUF->srcipaddr[0], 2 sizeof(uip_ipaddr_t));
frank26080115	0:bf7b9fba3924	362
frank26080115	0:bf7b9fba3924	363	/* Sum TCP header and data. */
frank26080115	0:bf7b9fba3924	364	sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN],
frank26080115	0:bf7b9fba3924	365	upper_layer_len);
frank26080115	0:bf7b9fba3924	366
frank26080115	0:bf7b9fba3924	367	return (sum == 0) ? 0xffff : htons(sum);
frank26080115	0:bf7b9fba3924	368	}
frank26080115	0:bf7b9fba3924	369	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	370	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	371	u16_t
frank26080115	0:bf7b9fba3924	372	uip_icmp6chksum(void)
frank26080115	0:bf7b9fba3924	373	{
frank26080115	0:bf7b9fba3924	374	return upper_layer_chksum(UIP_PROTO_ICMP6);
frank26080115	0:bf7b9fba3924	375
frank26080115	0:bf7b9fba3924	376	}
frank26080115	0:bf7b9fba3924	377	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	378	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	379	u16_t
frank26080115	0:bf7b9fba3924	380	uip_tcpchksum(void)
frank26080115	0:bf7b9fba3924	381	{
frank26080115	0:bf7b9fba3924	382	return upper_layer_chksum(UIP_PROTO_TCP);
frank26080115	0:bf7b9fba3924	383	}
frank26080115	0:bf7b9fba3924	384	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	385	#if UIP_UDP_CHECKSUMS
frank26080115	0:bf7b9fba3924	386	u16_t
frank26080115	0:bf7b9fba3924	387	uip_udpchksum(void)
frank26080115	0:bf7b9fba3924	388	{
frank26080115	0:bf7b9fba3924	389	return upper_layer_chksum(UIP_PROTO_UDP);
frank26080115	0:bf7b9fba3924	390	}
frank26080115	0:bf7b9fba3924	391	#endif /* UIP_UDP_CHECKSUMS */
frank26080115	0:bf7b9fba3924	392	#endif /* UIP_ARCH_CHKSUM */
frank26080115	0:bf7b9fba3924	393	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	394	void
frank26080115	0:bf7b9fba3924	395	uip_init(void)
frank26080115	0:bf7b9fba3924	396	{
frank26080115	0:bf7b9fba3924	397	for(c = 0; c < UIP_LISTENPORTS; ++c) {
frank26080115	0:bf7b9fba3924	398	uip_listenports[c] = 0;
frank26080115	0:bf7b9fba3924	399	}
frank26080115	0:bf7b9fba3924	400	for(c = 0; c < UIP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	401	uip_conns[c].tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	402	}
frank26080115	0:bf7b9fba3924	403	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	404	lastport = 1024;
frank26080115	0:bf7b9fba3924	405	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	406
frank26080115	0:bf7b9fba3924	407	#if UIP_UDP
frank26080115	0:bf7b9fba3924	408	for(c = 0; c < UIP_UDP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	409	uip_udp_conns[c].lport = 0;
frank26080115	0:bf7b9fba3924	410	}
frank26080115	0:bf7b9fba3924	411	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	412
frank26080115	0:bf7b9fba3924	413
frank26080115	0:bf7b9fba3924	414	/* IPv4 initialization. */
frank26080115	0:bf7b9fba3924	415	#if UIP_FIXEDADDR == 0
frank26080115	0:bf7b9fba3924	416	/* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
frank26080115	0:bf7b9fba3924	417	#endif /* UIP_FIXEDADDR */
frank26080115	0:bf7b9fba3924	418
frank26080115	0:bf7b9fba3924	419	}
frank26080115	0:bf7b9fba3924	420	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	421	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	422	struct uip_conn *
frank26080115	0:bf7b9fba3924	423	uip_connect(uip_ipaddr_t *ripaddr, u16_t rport)
frank26080115	0:bf7b9fba3924	424	{
frank26080115	0:bf7b9fba3924	425	register struct uip_conn conn, cconn;
frank26080115	0:bf7b9fba3924	426
frank26080115	0:bf7b9fba3924	427	/* Find an unused local port. */
frank26080115	0:bf7b9fba3924	428	again:
frank26080115	0:bf7b9fba3924	429	++lastport;
frank26080115	0:bf7b9fba3924	430
frank26080115	0:bf7b9fba3924	431	if(lastport >= 32000) {
frank26080115	0:bf7b9fba3924	432	lastport = 4096;
frank26080115	0:bf7b9fba3924	433	}
frank26080115	0:bf7b9fba3924	434
frank26080115	0:bf7b9fba3924	435	/* Check if this port is already in use, and if so try to find
frank26080115	0:bf7b9fba3924	436	another one. */
frank26080115	0:bf7b9fba3924	437	for(c = 0; c < UIP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	438	conn = &uip_conns[c];
frank26080115	0:bf7b9fba3924	439	if(conn->tcpstateflags != UIP_CLOSED &&
frank26080115	0:bf7b9fba3924	440	conn->lport == htons(lastport)) {
frank26080115	0:bf7b9fba3924	441	goto again;
frank26080115	0:bf7b9fba3924	442	}
frank26080115	0:bf7b9fba3924	443	}
frank26080115	0:bf7b9fba3924	444
frank26080115	0:bf7b9fba3924	445	conn = 0;
frank26080115	0:bf7b9fba3924	446	for(c = 0; c < UIP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	447	cconn = &uip_conns[c];
frank26080115	0:bf7b9fba3924	448	if(cconn->tcpstateflags == UIP_CLOSED) {
frank26080115	0:bf7b9fba3924	449	conn = cconn;
frank26080115	0:bf7b9fba3924	450	break;
frank26080115	0:bf7b9fba3924	451	}
frank26080115	0:bf7b9fba3924	452	if(cconn->tcpstateflags == UIP_TIME_WAIT) {
frank26080115	0:bf7b9fba3924	453	if(conn == 0 \|\|
frank26080115	0:bf7b9fba3924	454	cconn->timer > conn->timer) {
frank26080115	0:bf7b9fba3924	455	conn = cconn;
frank26080115	0:bf7b9fba3924	456	}
frank26080115	0:bf7b9fba3924	457	}
frank26080115	0:bf7b9fba3924	458	}
frank26080115	0:bf7b9fba3924	459
frank26080115	0:bf7b9fba3924	460	if(conn == 0) {
frank26080115	0:bf7b9fba3924	461	return 0;
frank26080115	0:bf7b9fba3924	462	}
frank26080115	0:bf7b9fba3924	463
frank26080115	0:bf7b9fba3924	464	conn->tcpstateflags = UIP_SYN_SENT;
frank26080115	0:bf7b9fba3924	465
frank26080115	0:bf7b9fba3924	466	conn->snd_nxt[0] = iss[0];
frank26080115	0:bf7b9fba3924	467	conn->snd_nxt[1] = iss[1];
frank26080115	0:bf7b9fba3924	468	conn->snd_nxt[2] = iss[2];
frank26080115	0:bf7b9fba3924	469	conn->snd_nxt[3] = iss[3];
frank26080115	0:bf7b9fba3924	470
frank26080115	0:bf7b9fba3924	471	conn->initialmss = conn->mss = UIP_TCP_MSS;
frank26080115	0:bf7b9fba3924	472
frank26080115	0:bf7b9fba3924	473	conn->len = 1; /* TCP length of the SYN is one. */
frank26080115	0:bf7b9fba3924	474	conn->nrtx = 0;
frank26080115	0:bf7b9fba3924	475	conn->timer = 1; /* Send the SYN next time around. */
frank26080115	0:bf7b9fba3924	476	conn->rto = UIP_RTO;
frank26080115	0:bf7b9fba3924	477	conn->sa = 0;
frank26080115	0:bf7b9fba3924	478	conn->sv = 16; /* Initial value of the RTT variance. */
frank26080115	0:bf7b9fba3924	479	conn->lport = htons(lastport);
frank26080115	0:bf7b9fba3924	480	conn->rport = rport;
frank26080115	0:bf7b9fba3924	481	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
frank26080115	0:bf7b9fba3924	482
frank26080115	0:bf7b9fba3924	483	return conn;
frank26080115	0:bf7b9fba3924	484	}
frank26080115	0:bf7b9fba3924	485	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	486	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	487	#if UIP_UDP
frank26080115	0:bf7b9fba3924	488	struct uip_udp_conn *
frank26080115	0:bf7b9fba3924	489	uip_udp_new(uip_ipaddr_t *ripaddr, u16_t rport)
frank26080115	0:bf7b9fba3924	490	{
frank26080115	0:bf7b9fba3924	491	register struct uip_udp_conn *conn;
frank26080115	0:bf7b9fba3924	492
frank26080115	0:bf7b9fba3924	493	/* Find an unused local port. */
frank26080115	0:bf7b9fba3924	494	again:
frank26080115	0:bf7b9fba3924	495	++lastport;
frank26080115	0:bf7b9fba3924	496
frank26080115	0:bf7b9fba3924	497	if(lastport >= 32000) {
frank26080115	0:bf7b9fba3924	498	lastport = 4096;
frank26080115	0:bf7b9fba3924	499	}
frank26080115	0:bf7b9fba3924	500
frank26080115	0:bf7b9fba3924	501	for(c = 0; c < UIP_UDP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	502	if(uip_udp_conns[c].lport == htons(lastport)) {
frank26080115	0:bf7b9fba3924	503	goto again;
frank26080115	0:bf7b9fba3924	504	}
frank26080115	0:bf7b9fba3924	505	}
frank26080115	0:bf7b9fba3924	506
frank26080115	0:bf7b9fba3924	507
frank26080115	0:bf7b9fba3924	508	conn = 0;
frank26080115	0:bf7b9fba3924	509	for(c = 0; c < UIP_UDP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	510	if(uip_udp_conns[c].lport == 0) {
frank26080115	0:bf7b9fba3924	511	conn = &uip_udp_conns[c];
frank26080115	0:bf7b9fba3924	512	break;
frank26080115	0:bf7b9fba3924	513	}
frank26080115	0:bf7b9fba3924	514	}
frank26080115	0:bf7b9fba3924	515
frank26080115	0:bf7b9fba3924	516	if(conn == 0) {
frank26080115	0:bf7b9fba3924	517	return 0;
frank26080115	0:bf7b9fba3924	518	}
frank26080115	0:bf7b9fba3924	519
frank26080115	0:bf7b9fba3924	520	conn->lport = HTONS(lastport);
frank26080115	0:bf7b9fba3924	521	conn->rport = rport;
frank26080115	0:bf7b9fba3924	522	if(ripaddr == NULL) {
frank26080115	0:bf7b9fba3924	523	memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
frank26080115	0:bf7b9fba3924	524	} else {
frank26080115	0:bf7b9fba3924	525	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
frank26080115	0:bf7b9fba3924	526	}
frank26080115	0:bf7b9fba3924	527	conn->ttl = UIP_TTL;
frank26080115	0:bf7b9fba3924	528
frank26080115	0:bf7b9fba3924	529	return conn;
frank26080115	0:bf7b9fba3924	530	}
frank26080115	0:bf7b9fba3924	531	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	532	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	533	void
frank26080115	0:bf7b9fba3924	534	uip_unlisten(u16_t port)
frank26080115	0:bf7b9fba3924	535	{
frank26080115	0:bf7b9fba3924	536	for(c = 0; c < UIP_LISTENPORTS; ++c) {
frank26080115	0:bf7b9fba3924	537	if(uip_listenports[c] == port) {
frank26080115	0:bf7b9fba3924	538	uip_listenports[c] = 0;
frank26080115	0:bf7b9fba3924	539	return;
frank26080115	0:bf7b9fba3924	540	}
frank26080115	0:bf7b9fba3924	541	}
frank26080115	0:bf7b9fba3924	542	}
frank26080115	0:bf7b9fba3924	543	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	544	void
frank26080115	0:bf7b9fba3924	545	uip_listen(u16_t port)
frank26080115	0:bf7b9fba3924	546	{
frank26080115	0:bf7b9fba3924	547	for(c = 0; c < UIP_LISTENPORTS; ++c) {
frank26080115	0:bf7b9fba3924	548	if(uip_listenports[c] == 0) {
frank26080115	0:bf7b9fba3924	549	uip_listenports[c] = port;
frank26080115	0:bf7b9fba3924	550	return;
frank26080115	0:bf7b9fba3924	551	}
frank26080115	0:bf7b9fba3924	552	}
frank26080115	0:bf7b9fba3924	553	}
frank26080115	0:bf7b9fba3924	554	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	555	/* XXX: IP fragment reassembly: not well-tested. */
frank26080115	0:bf7b9fba3924	556
frank26080115	0:bf7b9fba3924	557	#if UIP_REASSEMBLY && !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	558	#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
frank26080115	0:bf7b9fba3924	559	static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
frank26080115	0:bf7b9fba3924	560	static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
frank26080115	0:bf7b9fba3924	561	static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
frank26080115	0:bf7b9fba3924	562	0x0f, 0x07, 0x03, 0x01};
frank26080115	0:bf7b9fba3924	563	static u16_t uip_reasslen;
frank26080115	0:bf7b9fba3924	564	static u8_t uip_reassflags;
frank26080115	0:bf7b9fba3924	565	#define UIP_REASS_FLAG_LASTFRAG 0x01
frank26080115	0:bf7b9fba3924	566	static u8_t uip_reasstmr;
frank26080115	0:bf7b9fba3924	567
frank26080115	0:bf7b9fba3924	568	#define IP_MF 0x20
frank26080115	0:bf7b9fba3924	569
frank26080115	0:bf7b9fba3924	570	static u8_t
frank26080115	0:bf7b9fba3924	571	uip_reass(void)
frank26080115	0:bf7b9fba3924	572	{
frank26080115	0:bf7b9fba3924	573	u16_t offset, len;
frank26080115	0:bf7b9fba3924	574	u16_t i;
frank26080115	0:bf7b9fba3924	575
frank26080115	0:bf7b9fba3924	576	/* If ip_reasstmr is zero, no packet is present in the buffer, so we
frank26080115	0:bf7b9fba3924	577	write the IP header of the fragment into the reassembly
frank26080115	0:bf7b9fba3924	578	buffer. The timer is updated with the maximum age. */
frank26080115	0:bf7b9fba3924	579	if(uip_reasstmr == 0) {
frank26080115	0:bf7b9fba3924	580	memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
frank26080115	0:bf7b9fba3924	581	uip_reasstmr = UIP_REASS_MAXAGE;
frank26080115	0:bf7b9fba3924	582	uip_reassflags = 0;
frank26080115	0:bf7b9fba3924	583	/* Clear the bitmap. */
frank26080115	0:bf7b9fba3924	584	memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
frank26080115	0:bf7b9fba3924	585	}
frank26080115	0:bf7b9fba3924	586
frank26080115	0:bf7b9fba3924	587	/* Check if the incoming fragment matches the one currently present
frank26080115	0:bf7b9fba3924	588	in the reasembly buffer. If so, we proceed with copying the
frank26080115	0:bf7b9fba3924	589	fragment into the buffer. */
frank26080115	0:bf7b9fba3924	590	if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
frank26080115	0:bf7b9fba3924	591	BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
frank26080115	0:bf7b9fba3924	592	BUF->destipaddr[0] == FBUF->destipaddr[0] &&
frank26080115	0:bf7b9fba3924	593	BUF->destipaddr[1] == FBUF->destipaddr[1] &&
frank26080115	0:bf7b9fba3924	594	BUF->ipid[0] == FBUF->ipid[0] &&
frank26080115	0:bf7b9fba3924	595	BUF->ipid[1] == FBUF->ipid[1]) {
frank26080115	0:bf7b9fba3924	596
frank26080115	0:bf7b9fba3924	597	len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
frank26080115	0:bf7b9fba3924	598	offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
frank26080115	0:bf7b9fba3924	599
frank26080115	0:bf7b9fba3924	600	/* If the offset or the offset + fragment length overflows the
frank26080115	0:bf7b9fba3924	601	reassembly buffer, we discard the entire packet. */
frank26080115	0:bf7b9fba3924	602	if(offset > UIP_REASS_BUFSIZE \|\|
frank26080115	0:bf7b9fba3924	603	offset + len > UIP_REASS_BUFSIZE) {
frank26080115	0:bf7b9fba3924	604	uip_reasstmr = 0;
frank26080115	0:bf7b9fba3924	605	goto nullreturn;
frank26080115	0:bf7b9fba3924	606	}
frank26080115	0:bf7b9fba3924	607
frank26080115	0:bf7b9fba3924	608	/* Copy the fragment into the reassembly buffer, at the right
frank26080115	0:bf7b9fba3924	609	offset. */
frank26080115	0:bf7b9fba3924	610	memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
frank26080115	0:bf7b9fba3924	611	(char )BUF + (int)((BUF->vhl & 0x0f) 4),
frank26080115	0:bf7b9fba3924	612	len);
frank26080115	0:bf7b9fba3924	613
frank26080115	0:bf7b9fba3924	614	/* Update the bitmap. */
frank26080115	0:bf7b9fba3924	615	if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
frank26080115	0:bf7b9fba3924	616	/* If the two endpoints are in the same byte, we only update
frank26080115	0:bf7b9fba3924	617	that byte. */
frank26080115	0:bf7b9fba3924	618
frank26080115	0:bf7b9fba3924	619	uip_reassbitmap[offset / (8 * 8)] \|=
frank26080115	0:bf7b9fba3924	620	bitmap_bits[(offset / 8 ) & 7] &
frank26080115	0:bf7b9fba3924	621	~bitmap_bits[((offset + len) / 8 ) & 7];
frank26080115	0:bf7b9fba3924	622	} else {
frank26080115	0:bf7b9fba3924	623	/* If the two endpoints are in different bytes, we update the
frank26080115	0:bf7b9fba3924	624	bytes in the endpoints and fill the stuff inbetween with
frank26080115	0:bf7b9fba3924	625	0xff. */
frank26080115	0:bf7b9fba3924	626	uip_reassbitmap[offset / (8 * 8)] \|=
frank26080115	0:bf7b9fba3924	627	bitmap_bits[(offset / 8 ) & 7];
frank26080115	0:bf7b9fba3924	628	for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
frank26080115	0:bf7b9fba3924	629	uip_reassbitmap[i] = 0xff;
frank26080115	0:bf7b9fba3924	630	}
frank26080115	0:bf7b9fba3924	631	uip_reassbitmap[(offset + len) / (8 * 8)] \|=
frank26080115	0:bf7b9fba3924	632	~bitmap_bits[((offset + len) / 8 ) & 7];
frank26080115	0:bf7b9fba3924	633	}
frank26080115	0:bf7b9fba3924	634
frank26080115	0:bf7b9fba3924	635	/* If this fragment has the More Fragments flag set to zero, we
frank26080115	0:bf7b9fba3924	636	know that this is the last fragment, so we can calculate the
frank26080115	0:bf7b9fba3924	637	size of the entire packet. We also set the
frank26080115	0:bf7b9fba3924	638	IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
frank26080115	0:bf7b9fba3924	639	the final fragment. */
frank26080115	0:bf7b9fba3924	640
frank26080115	0:bf7b9fba3924	641	if((BUF->ipoffset[0] & IP_MF) == 0) {
frank26080115	0:bf7b9fba3924	642	uip_reassflags \|= UIP_REASS_FLAG_LASTFRAG;
frank26080115	0:bf7b9fba3924	643	uip_reasslen = offset + len;
frank26080115	0:bf7b9fba3924	644	}
frank26080115	0:bf7b9fba3924	645
frank26080115	0:bf7b9fba3924	646	/* Finally, we check if we have a full packet in the buffer. We do
frank26080115	0:bf7b9fba3924	647	this by checking if we have the last fragment and if all bits
frank26080115	0:bf7b9fba3924	648	in the bitmap are set. */
frank26080115	0:bf7b9fba3924	649	if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
frank26080115	0:bf7b9fba3924	650	/* Check all bytes up to and including all but the last byte in
frank26080115	0:bf7b9fba3924	651	the bitmap. */
frank26080115	0:bf7b9fba3924	652	for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
frank26080115	0:bf7b9fba3924	653	if(uip_reassbitmap[i] != 0xff) {
frank26080115	0:bf7b9fba3924	654	goto nullreturn;
frank26080115	0:bf7b9fba3924	655	}
frank26080115	0:bf7b9fba3924	656	}
frank26080115	0:bf7b9fba3924	657	/* Check the last byte in the bitmap. It should contain just the
frank26080115	0:bf7b9fba3924	658	right amount of bits. */
frank26080115	0:bf7b9fba3924	659	if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
frank26080115	0:bf7b9fba3924	660	(u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
frank26080115	0:bf7b9fba3924	661	goto nullreturn;
frank26080115	0:bf7b9fba3924	662	}
frank26080115	0:bf7b9fba3924	663
frank26080115	0:bf7b9fba3924	664	/* If we have come this far, we have a full packet in the
frank26080115	0:bf7b9fba3924	665	buffer, so we allocate a pbuf and copy the packet into it. We
frank26080115	0:bf7b9fba3924	666	also reset the timer. */
frank26080115	0:bf7b9fba3924	667	uip_reasstmr = 0;
frank26080115	0:bf7b9fba3924	668	memcpy(BUF, FBUF, uip_reasslen);
frank26080115	0:bf7b9fba3924	669
frank26080115	0:bf7b9fba3924	670	/* Pretend to be a "normal" (i.e., not fragmented) IP packet
frank26080115	0:bf7b9fba3924	671	from now on. */
frank26080115	0:bf7b9fba3924	672	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
frank26080115	0:bf7b9fba3924	673	BUF->len[0] = uip_reasslen >> 8;
frank26080115	0:bf7b9fba3924	674	BUF->len[1] = uip_reasslen & 0xff;
frank26080115	0:bf7b9fba3924	675	BUF->ipchksum = 0;
frank26080115	0:bf7b9fba3924	676	BUF->ipchksum = ~(uip_ipchksum());
frank26080115	0:bf7b9fba3924	677
frank26080115	0:bf7b9fba3924	678	return uip_reasslen;
frank26080115	0:bf7b9fba3924	679	}
frank26080115	0:bf7b9fba3924	680	}
frank26080115	0:bf7b9fba3924	681
frank26080115	0:bf7b9fba3924	682	nullreturn:
frank26080115	0:bf7b9fba3924	683	return 0;
frank26080115	0:bf7b9fba3924	684	}
frank26080115	0:bf7b9fba3924	685	#endif /* UIP_REASSEMBLY */
frank26080115	0:bf7b9fba3924	686	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	687	static void
frank26080115	0:bf7b9fba3924	688	uip_add_rcv_nxt(u16_t n)
frank26080115	0:bf7b9fba3924	689	{
frank26080115	0:bf7b9fba3924	690	uip_add32(uip_conn->rcv_nxt, n);
frank26080115	0:bf7b9fba3924	691	uip_conn->rcv_nxt[0] = uip_acc32[0];
frank26080115	0:bf7b9fba3924	692	uip_conn->rcv_nxt[1] = uip_acc32[1];
frank26080115	0:bf7b9fba3924	693	uip_conn->rcv_nxt[2] = uip_acc32[2];
frank26080115	0:bf7b9fba3924	694	uip_conn->rcv_nxt[3] = uip_acc32[3];
frank26080115	0:bf7b9fba3924	695	}
frank26080115	0:bf7b9fba3924	696	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	697	void
frank26080115	0:bf7b9fba3924	698	uip_process(u8_t flag)
frank26080115	0:bf7b9fba3924	699	{
frank26080115	0:bf7b9fba3924	700	register struct uip_conn *uip_connr = uip_conn;
frank26080115	0:bf7b9fba3924	701
frank26080115	0:bf7b9fba3924	702	#if UIP_UDP
frank26080115	0:bf7b9fba3924	703	if(flag == UIP_UDP_SEND_CONN) {
frank26080115	0:bf7b9fba3924	704	goto udp_send;
frank26080115	0:bf7b9fba3924	705	}
frank26080115	0:bf7b9fba3924	706	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	707
frank26080115	0:bf7b9fba3924	708	uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
frank26080115	0:bf7b9fba3924	709
frank26080115	0:bf7b9fba3924	710	/* Check if we were invoked because of a poll request for a
frank26080115	0:bf7b9fba3924	711	particular connection. */
frank26080115	0:bf7b9fba3924	712	if(flag == UIP_POLL_REQUEST) {
frank26080115	0:bf7b9fba3924	713	if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
frank26080115	0:bf7b9fba3924	714	!uip_outstanding(uip_connr)) {
frank26080115	0:bf7b9fba3924	715	uip_flags = UIP_POLL;
frank26080115	0:bf7b9fba3924	716	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	717	goto appsend;
frank26080115	0:bf7b9fba3924	718	}
frank26080115	0:bf7b9fba3924	719	goto drop;
frank26080115	0:bf7b9fba3924	720
frank26080115	0:bf7b9fba3924	721	/* Check if we were invoked because of the perodic timer fireing. */
frank26080115	0:bf7b9fba3924	722	} else if(flag == UIP_TIMER) {
frank26080115	0:bf7b9fba3924	723	#if UIP_REASSEMBLY
frank26080115	0:bf7b9fba3924	724	if(uip_reasstmr != 0) {
frank26080115	0:bf7b9fba3924	725	--uip_reasstmr;
frank26080115	0:bf7b9fba3924	726	}
frank26080115	0:bf7b9fba3924	727	#endif /* UIP_REASSEMBLY */
frank26080115	0:bf7b9fba3924	728	/* Increase the initial sequence number. */
frank26080115	0:bf7b9fba3924	729	if(++iss[3] == 0) {
frank26080115	0:bf7b9fba3924	730	if(++iss[2] == 0) {
frank26080115	0:bf7b9fba3924	731	if(++iss[1] == 0) {
frank26080115	0:bf7b9fba3924	732	++iss[0];
frank26080115	0:bf7b9fba3924	733	}
frank26080115	0:bf7b9fba3924	734	}
frank26080115	0:bf7b9fba3924	735	}
frank26080115	0:bf7b9fba3924	736
frank26080115	0:bf7b9fba3924	737	/* Reset the length variables. */
frank26080115	0:bf7b9fba3924	738	uip_len = 0;
frank26080115	0:bf7b9fba3924	739	uip_slen = 0;
frank26080115	0:bf7b9fba3924	740
frank26080115	0:bf7b9fba3924	741	/* Check if the connection is in a state in which we simply wait
frank26080115	0:bf7b9fba3924	742	for the connection to time out. If so, we increase the
frank26080115	0:bf7b9fba3924	743	connection's timer and remove the connection if it times
frank26080115	0:bf7b9fba3924	744	out. */
frank26080115	0:bf7b9fba3924	745	if(uip_connr->tcpstateflags == UIP_TIME_WAIT \|\|
frank26080115	0:bf7b9fba3924	746	uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
frank26080115	0:bf7b9fba3924	747	++(uip_connr->timer);
frank26080115	0:bf7b9fba3924	748	if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
frank26080115	0:bf7b9fba3924	749	uip_connr->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	750	}
frank26080115	0:bf7b9fba3924	751	} else if(uip_connr->tcpstateflags != UIP_CLOSED) {
frank26080115	0:bf7b9fba3924	752	/* If the connection has outstanding data, we increase the
frank26080115	0:bf7b9fba3924	753	connection's timer and see if it has reached the RTO value
frank26080115	0:bf7b9fba3924	754	in which case we retransmit. */
frank26080115	0:bf7b9fba3924	755	if(uip_outstanding(uip_connr)) {
frank26080115	0:bf7b9fba3924	756	uip_connr->timer = uip_connr->timer - 1;
frank26080115	0:bf7b9fba3924	757	if(uip_connr->timer == 0) {
frank26080115	0:bf7b9fba3924	758	if(uip_connr->nrtx == UIP_MAXRTX \|\|
frank26080115	0:bf7b9fba3924	759	((uip_connr->tcpstateflags == UIP_SYN_SENT \|\|
frank26080115	0:bf7b9fba3924	760	uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
frank26080115	0:bf7b9fba3924	761	uip_connr->nrtx == UIP_MAXSYNRTX)) {
frank26080115	0:bf7b9fba3924	762	uip_connr->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	763
frank26080115	0:bf7b9fba3924	764	/* We call UIP_APPCALL() with uip_flags set to
frank26080115	0:bf7b9fba3924	765	UIP_TIMEDOUT to inform the application that the
frank26080115	0:bf7b9fba3924	766	connection has timed out. */
frank26080115	0:bf7b9fba3924	767	uip_flags = UIP_TIMEDOUT;
frank26080115	0:bf7b9fba3924	768	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	769
frank26080115	0:bf7b9fba3924	770	/* We also send a reset packet to the remote host. */
frank26080115	0:bf7b9fba3924	771	BUF->flags = TCP_RST \| TCP_ACK;
frank26080115	0:bf7b9fba3924	772	goto tcp_send_nodata;
frank26080115	0:bf7b9fba3924	773	}
frank26080115	0:bf7b9fba3924	774
frank26080115	0:bf7b9fba3924	775	/* Exponential backoff. */
frank26080115	0:bf7b9fba3924	776	uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
frank26080115	0:bf7b9fba3924	777	4:
frank26080115	0:bf7b9fba3924	778	uip_connr->nrtx);
frank26080115	0:bf7b9fba3924	779	++(uip_connr->nrtx);
frank26080115	0:bf7b9fba3924	780
frank26080115	0:bf7b9fba3924	781	/* Ok, so we need to retransmit. We do this differently
frank26080115	0:bf7b9fba3924	782	depending on which state we are in. In ESTABLISHED, we
frank26080115	0:bf7b9fba3924	783	call upon the application so that it may prepare the
frank26080115	0:bf7b9fba3924	784	data for the retransmit. In SYN_RCVD, we resend the
frank26080115	0:bf7b9fba3924	785	SYNACK that we sent earlier and in LAST_ACK we have to
frank26080115	0:bf7b9fba3924	786	retransmit our FINACK. */
frank26080115	0:bf7b9fba3924	787	UIP_STAT(++uip_stat.tcp.rexmit);
frank26080115	0:bf7b9fba3924	788	switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
frank26080115	0:bf7b9fba3924	789	case UIP_SYN_RCVD:
frank26080115	0:bf7b9fba3924	790	/* In the SYN_RCVD state, we should retransmit our
frank26080115	0:bf7b9fba3924	791	SYNACK. */
frank26080115	0:bf7b9fba3924	792	goto tcp_send_synack;
frank26080115	0:bf7b9fba3924	793
frank26080115	0:bf7b9fba3924	794	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	795	case UIP_SYN_SENT:
frank26080115	0:bf7b9fba3924	796	/* In the SYN_SENT state, we retransmit out SYN. */
frank26080115	0:bf7b9fba3924	797	BUF->flags = 0;
frank26080115	0:bf7b9fba3924	798	goto tcp_send_syn;
frank26080115	0:bf7b9fba3924	799	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	800
frank26080115	0:bf7b9fba3924	801	case UIP_ESTABLISHED:
frank26080115	0:bf7b9fba3924	802	/* In the ESTABLISHED state, we call upon the application
frank26080115	0:bf7b9fba3924	803	to do the actual retransmit after which we jump into
frank26080115	0:bf7b9fba3924	804	the code for sending out the packet (the apprexmit
frank26080115	0:bf7b9fba3924	805	label). */
frank26080115	0:bf7b9fba3924	806	uip_flags = UIP_REXMIT;
frank26080115	0:bf7b9fba3924	807	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	808	goto apprexmit;
frank26080115	0:bf7b9fba3924	809
frank26080115	0:bf7b9fba3924	810	case UIP_FIN_WAIT_1:
frank26080115	0:bf7b9fba3924	811	case UIP_CLOSING:
frank26080115	0:bf7b9fba3924	812	case UIP_LAST_ACK:
frank26080115	0:bf7b9fba3924	813	/* In all these states we should retransmit a FINACK. */
frank26080115	0:bf7b9fba3924	814	goto tcp_send_finack;
frank26080115	0:bf7b9fba3924	815
frank26080115	0:bf7b9fba3924	816	}
frank26080115	0:bf7b9fba3924	817	}
frank26080115	0:bf7b9fba3924	818	} else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
frank26080115	0:bf7b9fba3924	819	/* If there was no need for a retransmission, we poll the
frank26080115	0:bf7b9fba3924	820	application for new data. */
frank26080115	0:bf7b9fba3924	821	uip_flags = UIP_POLL;
frank26080115	0:bf7b9fba3924	822	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	823	goto appsend;
frank26080115	0:bf7b9fba3924	824	}
frank26080115	0:bf7b9fba3924	825	}
frank26080115	0:bf7b9fba3924	826	goto drop;
frank26080115	0:bf7b9fba3924	827	}
frank26080115	0:bf7b9fba3924	828	#if UIP_UDP
frank26080115	0:bf7b9fba3924	829	if(flag == UIP_UDP_TIMER) {
frank26080115	0:bf7b9fba3924	830	if(uip_udp_conn->lport != 0) {
frank26080115	0:bf7b9fba3924	831	uip_conn = NULL;
frank26080115	0:bf7b9fba3924	832	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
frank26080115	0:bf7b9fba3924	833	uip_len = uip_slen = 0;
frank26080115	0:bf7b9fba3924	834	uip_flags = UIP_POLL;
frank26080115	0:bf7b9fba3924	835	UIP_UDP_APPCALL();
frank26080115	0:bf7b9fba3924	836	goto udp_send;
frank26080115	0:bf7b9fba3924	837	} else {
frank26080115	0:bf7b9fba3924	838	goto drop;
frank26080115	0:bf7b9fba3924	839	}
frank26080115	0:bf7b9fba3924	840	}
frank26080115	0:bf7b9fba3924	841	#endif
frank26080115	0:bf7b9fba3924	842
frank26080115	0:bf7b9fba3924	843	/* This is where the input processing starts. */
frank26080115	0:bf7b9fba3924	844	UIP_STAT(++uip_stat.ip.recv);
frank26080115	0:bf7b9fba3924	845
frank26080115	0:bf7b9fba3924	846	/* Start of IP input header processing code. */
frank26080115	0:bf7b9fba3924	847
frank26080115	0:bf7b9fba3924	848	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	849	/* Check validity of the IP header. */
frank26080115	0:bf7b9fba3924	850	if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
frank26080115	0:bf7b9fba3924	851	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	852	UIP_STAT(++uip_stat.ip.vhlerr);
frank26080115	0:bf7b9fba3924	853	UIP_LOG("ipv6: invalid version.");
frank26080115	0:bf7b9fba3924	854	goto drop;
frank26080115	0:bf7b9fba3924	855	}
frank26080115	0:bf7b9fba3924	856	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	857	/* Check validity of the IP header. */
frank26080115	0:bf7b9fba3924	858	if(BUF->vhl != 0x45) { /* IP version and header length. */
frank26080115	0:bf7b9fba3924	859	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	860	UIP_STAT(++uip_stat.ip.vhlerr);
frank26080115	0:bf7b9fba3924	861	UIP_LOG("ip: invalid version or header length.");
frank26080115	0:bf7b9fba3924	862	goto drop;
frank26080115	0:bf7b9fba3924	863	}
frank26080115	0:bf7b9fba3924	864	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	865
frank26080115	0:bf7b9fba3924	866	/* Check the size of the packet. If the size reported to us in
frank26080115	0:bf7b9fba3924	867	uip_len is smaller the size reported in the IP header, we assume
frank26080115	0:bf7b9fba3924	868	that the packet has been corrupted in transit. If the size of
frank26080115	0:bf7b9fba3924	869	uip_len is larger than the size reported in the IP packet header,
frank26080115	0:bf7b9fba3924	870	the packet has been padded and we set uip_len to the correct
frank26080115	0:bf7b9fba3924	871	value.. */
frank26080115	0:bf7b9fba3924	872
frank26080115	0:bf7b9fba3924	873	if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
frank26080115	0:bf7b9fba3924	874	uip_len = (BUF->len[0] << 8) + BUF->len[1];
frank26080115	0:bf7b9fba3924	875	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	876	uip_len += 40; /* The length reported in the IPv6 header is the
frank26080115	0:bf7b9fba3924	877	length of the payload that follows the
frank26080115	0:bf7b9fba3924	878	header. However, uIP uses the uip_len variable
frank26080115	0:bf7b9fba3924	879	for holding the size of the entire packet,
frank26080115	0:bf7b9fba3924	880	including the IP header. For IPv4 this is not a
frank26080115	0:bf7b9fba3924	881	problem as the length field in the IPv4 header
frank26080115	0:bf7b9fba3924	882	contains the length of the entire packet. But
frank26080115	0:bf7b9fba3924	883	for IPv6 we need to add the size of the IPv6
frank26080115	0:bf7b9fba3924	884	header (40 bytes). */
frank26080115	0:bf7b9fba3924	885	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	886	} else {
frank26080115	0:bf7b9fba3924	887	UIP_LOG("ip: packet shorter than reported in IP header.");
frank26080115	0:bf7b9fba3924	888	goto drop;
frank26080115	0:bf7b9fba3924	889	}
frank26080115	0:bf7b9fba3924	890
frank26080115	0:bf7b9fba3924	891	#if !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	892	/* Check the fragment flag. */
frank26080115	0:bf7b9fba3924	893	if((BUF->ipoffset[0] & 0x3f) != 0 \|\|
frank26080115	0:bf7b9fba3924	894	BUF->ipoffset[1] != 0) {
frank26080115	0:bf7b9fba3924	895	#if UIP_REASSEMBLY
frank26080115	0:bf7b9fba3924	896	uip_len = uip_reass();
frank26080115	0:bf7b9fba3924	897	if(uip_len == 0) {
frank26080115	0:bf7b9fba3924	898	goto drop;
frank26080115	0:bf7b9fba3924	899	}
frank26080115	0:bf7b9fba3924	900	#else /* UIP_REASSEMBLY */
frank26080115	0:bf7b9fba3924	901	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	902	UIP_STAT(++uip_stat.ip.fragerr);
frank26080115	0:bf7b9fba3924	903	UIP_LOG("ip: fragment dropped.");
frank26080115	0:bf7b9fba3924	904	goto drop;
frank26080115	0:bf7b9fba3924	905	#endif /* UIP_REASSEMBLY */
frank26080115	0:bf7b9fba3924	906	}
frank26080115	0:bf7b9fba3924	907	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	908
frank26080115	0:bf7b9fba3924	909	if(uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr)) {
frank26080115	0:bf7b9fba3924	910	/* If we are configured to use ping IP address configuration and
frank26080115	0:bf7b9fba3924	911	hasn't been assigned an IP address yet, we accept all ICMP
frank26080115	0:bf7b9fba3924	912	packets. */
frank26080115	0:bf7b9fba3924	913	#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	914	if(BUF->proto == UIP_PROTO_ICMP) {
frank26080115	0:bf7b9fba3924	915	UIP_LOG("ip: possible ping config packet received.");
frank26080115	0:bf7b9fba3924	916	goto icmp_input;
frank26080115	0:bf7b9fba3924	917	} else {
frank26080115	0:bf7b9fba3924	918	UIP_LOG("ip: packet dropped since no address assigned.");
frank26080115	0:bf7b9fba3924	919	goto drop;
frank26080115	0:bf7b9fba3924	920	}
frank26080115	0:bf7b9fba3924	921	#endif /* UIP_PINGADDRCONF */
frank26080115	0:bf7b9fba3924	922
frank26080115	0:bf7b9fba3924	923	} else {
frank26080115	0:bf7b9fba3924	924	/* If IP broadcast support is configured, we check for a broadcast
frank26080115	0:bf7b9fba3924	925	UDP packet, which may be destined to us. */
frank26080115	0:bf7b9fba3924	926	#if UIP_BROADCAST
frank26080115	0:bf7b9fba3924	927	DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
frank26080115	0:bf7b9fba3924	928	if(BUF->proto == UIP_PROTO_UDP &&
frank26080115	0:bf7b9fba3924	929	uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr)
frank26080115	0:bf7b9fba3924	930	/*&&
frank26080115	0:bf7b9fba3924	931	uip_ipchksum() == 0xffff*/) {
frank26080115	0:bf7b9fba3924	932	goto udp_input;
frank26080115	0:bf7b9fba3924	933	}
frank26080115	0:bf7b9fba3924	934	#endif /* UIP_BROADCAST */
frank26080115	0:bf7b9fba3924	935
frank26080115	0:bf7b9fba3924	936	/* Check if the packet is destined for our IP address. */
frank26080115	0:bf7b9fba3924	937	#if !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	938	if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
frank26080115	0:bf7b9fba3924	939	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	940	goto drop;
frank26080115	0:bf7b9fba3924	941	}
frank26080115	0:bf7b9fba3924	942	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	943	/* For IPv6, packet reception is a little trickier as we need to
frank26080115	0:bf7b9fba3924	944	make sure that we listen to certain multicast addresses (all
frank26080115	0:bf7b9fba3924	945	hosts multicast address, and the solicited-node multicast
frank26080115	0:bf7b9fba3924	946	address) as well. However, we will cheat here and accept all
frank26080115	0:bf7b9fba3924	947	multicast packets that are sent to the ff02::/16 addresses. */
frank26080115	0:bf7b9fba3924	948	if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) &&
frank26080115	0:bf7b9fba3924	949	BUF->destipaddr[0] != HTONS(0xff02)) {
frank26080115	0:bf7b9fba3924	950	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	951	goto drop;
frank26080115	0:bf7b9fba3924	952	}
frank26080115	0:bf7b9fba3924	953	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	954	}
frank26080115	0:bf7b9fba3924	955
frank26080115	0:bf7b9fba3924	956	#if !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	957	if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header
frank26080115	0:bf7b9fba3924	958	checksum. */
frank26080115	0:bf7b9fba3924	959	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	960	UIP_STAT(++uip_stat.ip.chkerr);
frank26080115	0:bf7b9fba3924	961	UIP_LOG("ip: bad checksum.");
frank26080115	0:bf7b9fba3924	962	goto drop;
frank26080115	0:bf7b9fba3924	963	}
frank26080115	0:bf7b9fba3924	964	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	965
frank26080115	0:bf7b9fba3924	966	if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so,
frank26080115	0:bf7b9fba3924	967	proceed with TCP input
frank26080115	0:bf7b9fba3924	968	processing. */
frank26080115	0:bf7b9fba3924	969	goto tcp_input;
frank26080115	0:bf7b9fba3924	970	}
frank26080115	0:bf7b9fba3924	971
frank26080115	0:bf7b9fba3924	972	#if UIP_UDP
frank26080115	0:bf7b9fba3924	973	if(BUF->proto == UIP_PROTO_UDP) {
frank26080115	0:bf7b9fba3924	974	goto udp_input;
frank26080115	0:bf7b9fba3924	975	}
frank26080115	0:bf7b9fba3924	976	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	977
frank26080115	0:bf7b9fba3924	978	#if !UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	979	/* ICMPv4 processing code follows. */
frank26080115	0:bf7b9fba3924	980	if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
frank26080115	0:bf7b9fba3924	981	here. */
frank26080115	0:bf7b9fba3924	982	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	983	UIP_STAT(++uip_stat.ip.protoerr);
frank26080115	0:bf7b9fba3924	984	UIP_LOG("ip: neither tcp nor icmp.");
frank26080115	0:bf7b9fba3924	985	goto drop;
frank26080115	0:bf7b9fba3924	986	}
frank26080115	0:bf7b9fba3924	987
frank26080115	0:bf7b9fba3924	988	#if UIP_PINGADDRCONF
frank26080115	0:bf7b9fba3924	989	icmp_input:
frank26080115	0:bf7b9fba3924	990	#endif /* UIP_PINGADDRCONF */
frank26080115	0:bf7b9fba3924	991	UIP_STAT(++uip_stat.icmp.recv);
frank26080115	0:bf7b9fba3924	992
frank26080115	0:bf7b9fba3924	993	/* ICMP echo (i.e., ping) processing. This is simple, we only change
frank26080115	0:bf7b9fba3924	994	the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
frank26080115	0:bf7b9fba3924	995	checksum before we return the packet. */
frank26080115	0:bf7b9fba3924	996	if(ICMPBUF->type != ICMP_ECHO) {
frank26080115	0:bf7b9fba3924	997	UIP_STAT(++uip_stat.icmp.drop);
frank26080115	0:bf7b9fba3924	998	UIP_STAT(++uip_stat.icmp.typeerr);
frank26080115	0:bf7b9fba3924	999	UIP_LOG("icmp: not icmp echo.");
frank26080115	0:bf7b9fba3924	1000	goto drop;
frank26080115	0:bf7b9fba3924	1001	}
frank26080115	0:bf7b9fba3924	1002
frank26080115	0:bf7b9fba3924	1003	/* If we are configured to use ping IP address assignment, we use
frank26080115	0:bf7b9fba3924	1004	the destination IP address of this ping packet and assign it to
frank26080115	0:bf7b9fba3924	1005	ourself. */
frank26080115	0:bf7b9fba3924	1006	#if UIP_PINGADDRCONF
frank26080115	0:bf7b9fba3924	1007	if((uip_hostaddr[0] \| uip_hostaddr[1]) == 0) {
frank26080115	0:bf7b9fba3924	1008	uip_hostaddr[0] = BUF->destipaddr[0];
frank26080115	0:bf7b9fba3924	1009	uip_hostaddr[1] = BUF->destipaddr[1];
frank26080115	0:bf7b9fba3924	1010	}
frank26080115	0:bf7b9fba3924	1011	#endif /* UIP_PINGADDRCONF */
frank26080115	0:bf7b9fba3924	1012
frank26080115	0:bf7b9fba3924	1013	ICMPBUF->type = ICMP_ECHO_REPLY;
frank26080115	0:bf7b9fba3924	1014
frank26080115	0:bf7b9fba3924	1015	if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
frank26080115	0:bf7b9fba3924	1016	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
frank26080115	0:bf7b9fba3924	1017	} else {
frank26080115	0:bf7b9fba3924	1018	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
frank26080115	0:bf7b9fba3924	1019	}
frank26080115	0:bf7b9fba3924	1020
frank26080115	0:bf7b9fba3924	1021	/* Swap IP addresses. */
frank26080115	0:bf7b9fba3924	1022	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
frank26080115	0:bf7b9fba3924	1023	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1024
frank26080115	0:bf7b9fba3924	1025	UIP_STAT(++uip_stat.icmp.sent);
frank26080115	0:bf7b9fba3924	1026	goto send;
frank26080115	0:bf7b9fba3924	1027
frank26080115	0:bf7b9fba3924	1028	/* End of IPv4 input header processing code. */
frank26080115	0:bf7b9fba3924	1029	#else /* !UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1030
frank26080115	0:bf7b9fba3924	1031	/* This is IPv6 ICMPv6 processing code. */
frank26080115	0:bf7b9fba3924	1032	DEBUG_PRINTF("icmp6_input: length %d\n", uip_len);
frank26080115	0:bf7b9fba3924	1033
frank26080115	0:bf7b9fba3924	1034	if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from
frank26080115	0:bf7b9fba3924	1035	here. */
frank26080115	0:bf7b9fba3924	1036	UIP_STAT(++uip_stat.ip.drop);
frank26080115	0:bf7b9fba3924	1037	UIP_STAT(++uip_stat.ip.protoerr);
frank26080115	0:bf7b9fba3924	1038	UIP_LOG("ip: neither tcp nor icmp6.");
frank26080115	0:bf7b9fba3924	1039	goto drop;
frank26080115	0:bf7b9fba3924	1040	}
frank26080115	0:bf7b9fba3924	1041
frank26080115	0:bf7b9fba3924	1042	UIP_STAT(++uip_stat.icmp.recv);
frank26080115	0:bf7b9fba3924	1043
frank26080115	0:bf7b9fba3924	1044	/* If we get a neighbor solicitation for our address we should send
frank26080115	0:bf7b9fba3924	1045	a neighbor advertisement message back. */
frank26080115	0:bf7b9fba3924	1046	if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
frank26080115	0:bf7b9fba3924	1047	if(uip_ipaddr_cmp(ICMPBUF->icmp6data, uip_hostaddr)) {
frank26080115	0:bf7b9fba3924	1048
frank26080115	0:bf7b9fba3924	1049	if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
frank26080115	0:bf7b9fba3924	1050	/* Save the sender's address in our neighbor list. */
frank26080115	0:bf7b9fba3924	1051	uip_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
frank26080115	0:bf7b9fba3924	1052	}
frank26080115	0:bf7b9fba3924	1053
frank26080115	0:bf7b9fba3924	1054	/* We should now send a neighbor advertisement back to where the
frank26080115	0:bf7b9fba3924	1055	neighbor solicication came from. */
frank26080115	0:bf7b9fba3924	1056	ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
frank26080115	0:bf7b9fba3924	1057	ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
frank26080115	0:bf7b9fba3924	1058
frank26080115	0:bf7b9fba3924	1059	ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
frank26080115	0:bf7b9fba3924	1060
frank26080115	0:bf7b9fba3924	1061	uip_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
frank26080115	0:bf7b9fba3924	1062	uip_ipaddr_copy(ICMPBUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1063	ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
frank26080115	0:bf7b9fba3924	1064	ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
frank26080115	0:bf7b9fba3924	1065	memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
frank26080115	0:bf7b9fba3924	1066	ICMPBUF->icmpchksum = 0;
frank26080115	0:bf7b9fba3924	1067	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
frank26080115	0:bf7b9fba3924	1068	goto send;
frank26080115	0:bf7b9fba3924	1069
frank26080115	0:bf7b9fba3924	1070	}
frank26080115	0:bf7b9fba3924	1071	goto drop;
frank26080115	0:bf7b9fba3924	1072	} else if(ICMPBUF->type == ICMP6_ECHO) {
frank26080115	0:bf7b9fba3924	1073	/* ICMP echo (i.e., ping) processing. This is simple, we only
frank26080115	0:bf7b9fba3924	1074	change the ICMP type from ECHO to ECHO_REPLY and update the
frank26080115	0:bf7b9fba3924	1075	ICMP checksum before we return the packet. */
frank26080115	0:bf7b9fba3924	1076
frank26080115	0:bf7b9fba3924	1077	ICMPBUF->type = ICMP6_ECHO_REPLY;
frank26080115	0:bf7b9fba3924	1078
frank26080115	0:bf7b9fba3924	1079	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
frank26080115	0:bf7b9fba3924	1080	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1081	ICMPBUF->icmpchksum = 0;
frank26080115	0:bf7b9fba3924	1082	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
frank26080115	0:bf7b9fba3924	1083
frank26080115	0:bf7b9fba3924	1084	UIP_STAT(++uip_stat.icmp.sent);
frank26080115	0:bf7b9fba3924	1085	goto send;
frank26080115	0:bf7b9fba3924	1086	} else {
frank26080115	0:bf7b9fba3924	1087	DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type);
frank26080115	0:bf7b9fba3924	1088	UIP_STAT(++uip_stat.icmp.drop);
frank26080115	0:bf7b9fba3924	1089	UIP_STAT(++uip_stat.icmp.typeerr);
frank26080115	0:bf7b9fba3924	1090	UIP_LOG("icmp: unknown ICMP message.");
frank26080115	0:bf7b9fba3924	1091	goto drop;
frank26080115	0:bf7b9fba3924	1092	}
frank26080115	0:bf7b9fba3924	1093
frank26080115	0:bf7b9fba3924	1094	/* End of IPv6 ICMP processing. */
frank26080115	0:bf7b9fba3924	1095
frank26080115	0:bf7b9fba3924	1096	#endif /* !UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1097
frank26080115	0:bf7b9fba3924	1098	#if UIP_UDP
frank26080115	0:bf7b9fba3924	1099	/* UDP input processing. */
frank26080115	0:bf7b9fba3924	1100	udp_input:
frank26080115	0:bf7b9fba3924	1101	/* UDP processing is really just a hack. We don't do anything to the
frank26080115	0:bf7b9fba3924	1102	UDP/IP headers, but let the UDP application do all the hard
frank26080115	0:bf7b9fba3924	1103	work. If the application sets uip_slen, it has a packet to
frank26080115	0:bf7b9fba3924	1104	send. */
frank26080115	0:bf7b9fba3924	1105	#if UIP_UDP_CHECKSUMS
frank26080115	0:bf7b9fba3924	1106	uip_len = uip_len - UIP_IPUDPH_LEN;
frank26080115	0:bf7b9fba3924	1107	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
frank26080115	0:bf7b9fba3924	1108	if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
frank26080115	0:bf7b9fba3924	1109	UIP_STAT(++uip_stat.udp.drop);
frank26080115	0:bf7b9fba3924	1110	UIP_STAT(++uip_stat.udp.chkerr);
frank26080115	0:bf7b9fba3924	1111	UIP_LOG("udp: bad checksum.");
frank26080115	0:bf7b9fba3924	1112	goto drop;
frank26080115	0:bf7b9fba3924	1113	}
frank26080115	0:bf7b9fba3924	1114	#else /* UIP_UDP_CHECKSUMS */
frank26080115	0:bf7b9fba3924	1115	uip_len = uip_len - UIP_IPUDPH_LEN;
frank26080115	0:bf7b9fba3924	1116	#endif /* UIP_UDP_CHECKSUMS */
frank26080115	0:bf7b9fba3924	1117
frank26080115	0:bf7b9fba3924	1118	/* Demultiplex this UDP packet between the UDP "connections". */
frank26080115	0:bf7b9fba3924	1119	for(uip_udp_conn = &uip_udp_conns[0];
frank26080115	0:bf7b9fba3924	1120	uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS];
frank26080115	0:bf7b9fba3924	1121	++uip_udp_conn) {
frank26080115	0:bf7b9fba3924	1122	/* If the local UDP port is non-zero, the connection is considered
frank26080115	0:bf7b9fba3924	1123	to be used. If so, the local port number is checked against the
frank26080115	0:bf7b9fba3924	1124	destination port number in the received packet. If the two port
frank26080115	0:bf7b9fba3924	1125	numbers match, the remote port number is checked if the
frank26080115	0:bf7b9fba3924	1126	connection is bound to a remote port. Finally, if the
frank26080115	0:bf7b9fba3924	1127	connection is bound to a remote IP address, the source IP
frank26080115	0:bf7b9fba3924	1128	address of the packet is checked. */
frank26080115	0:bf7b9fba3924	1129	if(uip_udp_conn->lport != 0 &&
frank26080115	0:bf7b9fba3924	1130	UDPBUF->destport == uip_udp_conn->lport &&
frank26080115	0:bf7b9fba3924	1131	(uip_udp_conn->rport == 0 \|\|
frank26080115	0:bf7b9fba3924	1132	UDPBUF->srcport == uip_udp_conn->rport) &&
frank26080115	0:bf7b9fba3924	1133	(uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_zeroes_addr) \|\|
frank26080115	0:bf7b9fba3924	1134	uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_ones_addr) \|\|
frank26080115	0:bf7b9fba3924	1135	uip_ipaddr_cmp(BUF->srcipaddr, uip_udp_conn->ripaddr))) {
frank26080115	0:bf7b9fba3924	1136	goto udp_found;
frank26080115	0:bf7b9fba3924	1137	}
frank26080115	0:bf7b9fba3924	1138	}
frank26080115	0:bf7b9fba3924	1139	UIP_LOG("udp: no matching connection found");
frank26080115	0:bf7b9fba3924	1140	goto drop;
frank26080115	0:bf7b9fba3924	1141
frank26080115	0:bf7b9fba3924	1142	udp_found:
frank26080115	0:bf7b9fba3924	1143	UIP_STAT(++uip_stat.udp.recv);
frank26080115	0:bf7b9fba3924	1144	uip_conn = NULL;
frank26080115	0:bf7b9fba3924	1145	uip_flags = UIP_NEWDATA;
frank26080115	0:bf7b9fba3924	1146	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
frank26080115	0:bf7b9fba3924	1147	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1148	UIP_UDP_APPCALL();
frank26080115	0:bf7b9fba3924	1149	udp_send:
frank26080115	0:bf7b9fba3924	1150	if(uip_slen == 0) {
frank26080115	0:bf7b9fba3924	1151	goto drop;
frank26080115	0:bf7b9fba3924	1152	}
frank26080115	0:bf7b9fba3924	1153	uip_len = uip_slen + UIP_IPUDPH_LEN;
frank26080115	0:bf7b9fba3924	1154
frank26080115	0:bf7b9fba3924	1155	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	1156	/* For IPv6, the IP length field does not include the IPv6 IP header
frank26080115	0:bf7b9fba3924	1157	length. */
frank26080115	0:bf7b9fba3924	1158	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
frank26080115	0:bf7b9fba3924	1159	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
frank26080115	0:bf7b9fba3924	1160	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1161	BUF->len[0] = (uip_len >> 8);
frank26080115	0:bf7b9fba3924	1162	BUF->len[1] = (uip_len & 0xff);
frank26080115	0:bf7b9fba3924	1163	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1164
frank26080115	0:bf7b9fba3924	1165	BUF->ttl = uip_udp_conn->ttl;
frank26080115	0:bf7b9fba3924	1166	BUF->proto = UIP_PROTO_UDP;
frank26080115	0:bf7b9fba3924	1167
frank26080115	0:bf7b9fba3924	1168	UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
frank26080115	0:bf7b9fba3924	1169	UDPBUF->udpchksum = 0;
frank26080115	0:bf7b9fba3924	1170
frank26080115	0:bf7b9fba3924	1171	BUF->srcport = uip_udp_conn->lport;
frank26080115	0:bf7b9fba3924	1172	BUF->destport = uip_udp_conn->rport;
frank26080115	0:bf7b9fba3924	1173
frank26080115	0:bf7b9fba3924	1174	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1175	uip_ipaddr_copy(BUF->destipaddr, uip_udp_conn->ripaddr);
frank26080115	0:bf7b9fba3924	1176
frank26080115	0:bf7b9fba3924	1177	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];
frank26080115	0:bf7b9fba3924	1178
frank26080115	0:bf7b9fba3924	1179	#if UIP_UDP_CHECKSUMS
frank26080115	0:bf7b9fba3924	1180	/* Calculate UDP checksum. */
frank26080115	0:bf7b9fba3924	1181	UDPBUF->udpchksum = ~(uip_udpchksum());
frank26080115	0:bf7b9fba3924	1182	if(UDPBUF->udpchksum == 0) {
frank26080115	0:bf7b9fba3924	1183	UDPBUF->udpchksum = 0xffff;
frank26080115	0:bf7b9fba3924	1184	}
frank26080115	0:bf7b9fba3924	1185	#endif /* UIP_UDP_CHECKSUMS */
frank26080115	0:bf7b9fba3924	1186	UIP_STAT(++uip_stat.udp.sent);
frank26080115	0:bf7b9fba3924	1187	goto ip_send_nolen;
frank26080115	0:bf7b9fba3924	1188	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	1189
frank26080115	0:bf7b9fba3924	1190	/* TCP input processing. */
frank26080115	0:bf7b9fba3924	1191	tcp_input:
frank26080115	0:bf7b9fba3924	1192	UIP_STAT(++uip_stat.tcp.recv);
frank26080115	0:bf7b9fba3924	1193
frank26080115	0:bf7b9fba3924	1194	/* Start of TCP input header processing code. */
frank26080115	0:bf7b9fba3924	1195
frank26080115	0:bf7b9fba3924	1196	if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP
frank26080115	0:bf7b9fba3924	1197	checksum. */
frank26080115	0:bf7b9fba3924	1198	UIP_STAT(++uip_stat.tcp.drop);
frank26080115	0:bf7b9fba3924	1199	UIP_STAT(++uip_stat.tcp.chkerr);
frank26080115	0:bf7b9fba3924	1200	UIP_LOG("tcp: bad checksum.");
frank26080115	0:bf7b9fba3924	1201	goto drop;
frank26080115	0:bf7b9fba3924	1202	}
frank26080115	0:bf7b9fba3924	1203
frank26080115	0:bf7b9fba3924	1204
frank26080115	0:bf7b9fba3924	1205	/* Demultiplex this segment. */
frank26080115	0:bf7b9fba3924	1206	/* First check any active connections. */
frank26080115	0:bf7b9fba3924	1207	for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1];
frank26080115	0:bf7b9fba3924	1208	++uip_connr) {
frank26080115	0:bf7b9fba3924	1209	if(uip_connr->tcpstateflags != UIP_CLOSED &&
frank26080115	0:bf7b9fba3924	1210	BUF->destport == uip_connr->lport &&
frank26080115	0:bf7b9fba3924	1211	BUF->srcport == uip_connr->rport &&
frank26080115	0:bf7b9fba3924	1212	uip_ipaddr_cmp(BUF->srcipaddr, uip_connr->ripaddr)) {
frank26080115	0:bf7b9fba3924	1213	goto found;
frank26080115	0:bf7b9fba3924	1214	}
frank26080115	0:bf7b9fba3924	1215	}
frank26080115	0:bf7b9fba3924	1216
frank26080115	0:bf7b9fba3924	1217	/* If we didn't find and active connection that expected the packet,
frank26080115	0:bf7b9fba3924	1218	either this packet is an old duplicate, or this is a SYN packet
frank26080115	0:bf7b9fba3924	1219	destined for a connection in LISTEN. If the SYN flag isn't set,
frank26080115	0:bf7b9fba3924	1220	it is an old packet and we send a RST. */
frank26080115	0:bf7b9fba3924	1221	if((BUF->flags & TCP_CTL) != TCP_SYN) {
frank26080115	0:bf7b9fba3924	1222	goto reset;
frank26080115	0:bf7b9fba3924	1223	}
frank26080115	0:bf7b9fba3924	1224
frank26080115	0:bf7b9fba3924	1225	tmp16 = BUF->destport;
frank26080115	0:bf7b9fba3924	1226	/* Next, check listening connections. */
frank26080115	0:bf7b9fba3924	1227	for(c = 0; c < UIP_LISTENPORTS; ++c) {
frank26080115	0:bf7b9fba3924	1228	if(tmp16 == uip_listenports[c])
frank26080115	0:bf7b9fba3924	1229	goto found_listen;
frank26080115	0:bf7b9fba3924	1230	}
frank26080115	0:bf7b9fba3924	1231
frank26080115	0:bf7b9fba3924	1232	/* No matching connection found, so we send a RST packet. */
frank26080115	0:bf7b9fba3924	1233	UIP_STAT(++uip_stat.tcp.synrst);
frank26080115	0:bf7b9fba3924	1234	reset:
frank26080115	0:bf7b9fba3924	1235
frank26080115	0:bf7b9fba3924	1236	/* We do not send resets in response to resets. */
frank26080115	0:bf7b9fba3924	1237	if(BUF->flags & TCP_RST) {
frank26080115	0:bf7b9fba3924	1238	goto drop;
frank26080115	0:bf7b9fba3924	1239	}
frank26080115	0:bf7b9fba3924	1240
frank26080115	0:bf7b9fba3924	1241	UIP_STAT(++uip_stat.tcp.rst);
frank26080115	0:bf7b9fba3924	1242
frank26080115	0:bf7b9fba3924	1243	BUF->flags = TCP_RST \| TCP_ACK;
frank26080115	0:bf7b9fba3924	1244	uip_len = UIP_IPTCPH_LEN;
frank26080115	0:bf7b9fba3924	1245	BUF->tcpoffset = 5 << 4;
frank26080115	0:bf7b9fba3924	1246
frank26080115	0:bf7b9fba3924	1247	/* Flip the seqno and ackno fields in the TCP header. */
frank26080115	0:bf7b9fba3924	1248	c = BUF->seqno[3];
frank26080115	0:bf7b9fba3924	1249	BUF->seqno[3] = BUF->ackno[3];
frank26080115	0:bf7b9fba3924	1250	BUF->ackno[3] = c;
frank26080115	0:bf7b9fba3924	1251
frank26080115	0:bf7b9fba3924	1252	c = BUF->seqno[2];
frank26080115	0:bf7b9fba3924	1253	BUF->seqno[2] = BUF->ackno[2];
frank26080115	0:bf7b9fba3924	1254	BUF->ackno[2] = c;
frank26080115	0:bf7b9fba3924	1255
frank26080115	0:bf7b9fba3924	1256	c = BUF->seqno[1];
frank26080115	0:bf7b9fba3924	1257	BUF->seqno[1] = BUF->ackno[1];
frank26080115	0:bf7b9fba3924	1258	BUF->ackno[1] = c;
frank26080115	0:bf7b9fba3924	1259
frank26080115	0:bf7b9fba3924	1260	c = BUF->seqno[0];
frank26080115	0:bf7b9fba3924	1261	BUF->seqno[0] = BUF->ackno[0];
frank26080115	0:bf7b9fba3924	1262	BUF->ackno[0] = c;
frank26080115	0:bf7b9fba3924	1263
frank26080115	0:bf7b9fba3924	1264	/* We also have to increase the sequence number we are
frank26080115	0:bf7b9fba3924	1265	acknowledging. If the least significant byte overflowed, we need
frank26080115	0:bf7b9fba3924	1266	to propagate the carry to the other bytes as well. */
frank26080115	0:bf7b9fba3924	1267	if(++BUF->ackno[3] == 0) {
frank26080115	0:bf7b9fba3924	1268	if(++BUF->ackno[2] == 0) {
frank26080115	0:bf7b9fba3924	1269	if(++BUF->ackno[1] == 0) {
frank26080115	0:bf7b9fba3924	1270	++BUF->ackno[0];
frank26080115	0:bf7b9fba3924	1271	}
frank26080115	0:bf7b9fba3924	1272	}
frank26080115	0:bf7b9fba3924	1273	}
frank26080115	0:bf7b9fba3924	1274
frank26080115	0:bf7b9fba3924	1275	/* Swap port numbers. */
frank26080115	0:bf7b9fba3924	1276	tmp16 = BUF->srcport;
frank26080115	0:bf7b9fba3924	1277	BUF->srcport = BUF->destport;
frank26080115	0:bf7b9fba3924	1278	BUF->destport = tmp16;
frank26080115	0:bf7b9fba3924	1279
frank26080115	0:bf7b9fba3924	1280	/* Swap IP addresses. */
frank26080115	0:bf7b9fba3924	1281	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
frank26080115	0:bf7b9fba3924	1282	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1283
frank26080115	0:bf7b9fba3924	1284	/* And send out the RST packet! */
frank26080115	0:bf7b9fba3924	1285	goto tcp_send_noconn;
frank26080115	0:bf7b9fba3924	1286
frank26080115	0:bf7b9fba3924	1287	/* This label will be jumped to if we matched the incoming packet
frank26080115	0:bf7b9fba3924	1288	with a connection in LISTEN. In that case, we should create a new
frank26080115	0:bf7b9fba3924	1289	connection and send a SYNACK in return. */
frank26080115	0:bf7b9fba3924	1290	found_listen:
frank26080115	0:bf7b9fba3924	1291	/* First we check if there are any connections avaliable. Unused
frank26080115	0:bf7b9fba3924	1292	connections are kept in the same table as used connections, but
frank26080115	0:bf7b9fba3924	1293	unused ones have the tcpstate set to CLOSED. Also, connections in
frank26080115	0:bf7b9fba3924	1294	TIME_WAIT are kept track of and we'll use the oldest one if no
frank26080115	0:bf7b9fba3924	1295	CLOSED connections are found. Thanks to Eddie C. Dost for a very
frank26080115	0:bf7b9fba3924	1296	nice algorithm for the TIME_WAIT search. */
frank26080115	0:bf7b9fba3924	1297	uip_connr = 0;
frank26080115	0:bf7b9fba3924	1298	for(c = 0; c < UIP_CONNS; ++c) {
frank26080115	0:bf7b9fba3924	1299	if(uip_conns[c].tcpstateflags == UIP_CLOSED) {
frank26080115	0:bf7b9fba3924	1300	uip_connr = &uip_conns[c];
frank26080115	0:bf7b9fba3924	1301	break;
frank26080115	0:bf7b9fba3924	1302	}
frank26080115	0:bf7b9fba3924	1303	if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
frank26080115	0:bf7b9fba3924	1304	if(uip_connr == 0 \|\|
frank26080115	0:bf7b9fba3924	1305	uip_conns[c].timer > uip_connr->timer) {
frank26080115	0:bf7b9fba3924	1306	uip_connr = &uip_conns[c];
frank26080115	0:bf7b9fba3924	1307	}
frank26080115	0:bf7b9fba3924	1308	}
frank26080115	0:bf7b9fba3924	1309	}
frank26080115	0:bf7b9fba3924	1310
frank26080115	0:bf7b9fba3924	1311	if(uip_connr == 0) {
frank26080115	0:bf7b9fba3924	1312	/* All connections are used already, we drop packet and hope that
frank26080115	0:bf7b9fba3924	1313	the remote end will retransmit the packet at a time when we
frank26080115	0:bf7b9fba3924	1314	have more spare connections. */
frank26080115	0:bf7b9fba3924	1315	UIP_STAT(++uip_stat.tcp.syndrop);
frank26080115	0:bf7b9fba3924	1316	UIP_LOG("tcp: found no unused connections.");
frank26080115	0:bf7b9fba3924	1317	goto drop;
frank26080115	0:bf7b9fba3924	1318	}
frank26080115	0:bf7b9fba3924	1319	uip_conn = uip_connr;
frank26080115	0:bf7b9fba3924	1320
frank26080115	0:bf7b9fba3924	1321	/* Fill in the necessary fields for the new connection. */
frank26080115	0:bf7b9fba3924	1322	uip_connr->rto = uip_connr->timer = UIP_RTO;
frank26080115	0:bf7b9fba3924	1323	uip_connr->sa = 0;
frank26080115	0:bf7b9fba3924	1324	uip_connr->sv = 4;
frank26080115	0:bf7b9fba3924	1325	uip_connr->nrtx = 0;
frank26080115	0:bf7b9fba3924	1326	uip_connr->lport = BUF->destport;
frank26080115	0:bf7b9fba3924	1327	uip_connr->rport = BUF->srcport;
frank26080115	0:bf7b9fba3924	1328	uip_ipaddr_copy(uip_connr->ripaddr, BUF->srcipaddr);
frank26080115	0:bf7b9fba3924	1329	uip_connr->tcpstateflags = UIP_SYN_RCVD;
frank26080115	0:bf7b9fba3924	1330
frank26080115	0:bf7b9fba3924	1331	uip_connr->snd_nxt[0] = iss[0];
frank26080115	0:bf7b9fba3924	1332	uip_connr->snd_nxt[1] = iss[1];
frank26080115	0:bf7b9fba3924	1333	uip_connr->snd_nxt[2] = iss[2];
frank26080115	0:bf7b9fba3924	1334	uip_connr->snd_nxt[3] = iss[3];
frank26080115	0:bf7b9fba3924	1335	uip_connr->len = 1;
frank26080115	0:bf7b9fba3924	1336
frank26080115	0:bf7b9fba3924	1337	/* rcv_nxt should be the seqno from the incoming packet + 1. */
frank26080115	0:bf7b9fba3924	1338	uip_connr->rcv_nxt[3] = BUF->seqno[3];
frank26080115	0:bf7b9fba3924	1339	uip_connr->rcv_nxt[2] = BUF->seqno[2];
frank26080115	0:bf7b9fba3924	1340	uip_connr->rcv_nxt[1] = BUF->seqno[1];
frank26080115	0:bf7b9fba3924	1341	uip_connr->rcv_nxt[0] = BUF->seqno[0];
frank26080115	0:bf7b9fba3924	1342	uip_add_rcv_nxt(1);
frank26080115	0:bf7b9fba3924	1343
frank26080115	0:bf7b9fba3924	1344	/* Parse the TCP MSS option, if present. */
frank26080115	0:bf7b9fba3924	1345	if((BUF->tcpoffset & 0xf0) > 0x50) {
frank26080115	0:bf7b9fba3924	1346	for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
frank26080115	0:bf7b9fba3924	1347	opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
frank26080115	0:bf7b9fba3924	1348	if(opt == TCP_OPT_END) {
frank26080115	0:bf7b9fba3924	1349	/* End of options. */
frank26080115	0:bf7b9fba3924	1350	break;
frank26080115	0:bf7b9fba3924	1351	} else if(opt == TCP_OPT_NOOP) {
frank26080115	0:bf7b9fba3924	1352	++c;
frank26080115	0:bf7b9fba3924	1353	/* NOP option. */
frank26080115	0:bf7b9fba3924	1354	} else if(opt == TCP_OPT_MSS &&
frank26080115	0:bf7b9fba3924	1355	uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
frank26080115	0:bf7b9fba3924	1356	/* An MSS option with the right option length. */
frank26080115	0:bf7b9fba3924	1357	tmp16 = ((u16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) \|
frank26080115	0:bf7b9fba3924	1358	(u16_t)uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c];
frank26080115	0:bf7b9fba3924	1359	uip_connr->initialmss = uip_connr->mss =
frank26080115	0:bf7b9fba3924	1360	tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
frank26080115	0:bf7b9fba3924	1361
frank26080115	0:bf7b9fba3924	1362	/* And we are done processing options. */
frank26080115	0:bf7b9fba3924	1363	break;
frank26080115	0:bf7b9fba3924	1364	} else {
frank26080115	0:bf7b9fba3924	1365	/* All other options have a length field, so that we easily
frank26080115	0:bf7b9fba3924	1366	can skip past them. */
frank26080115	0:bf7b9fba3924	1367	if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
frank26080115	0:bf7b9fba3924	1368	/* If the length field is zero, the options are malformed
frank26080115	0:bf7b9fba3924	1369	and we don't process them further. */
frank26080115	0:bf7b9fba3924	1370	break;
frank26080115	0:bf7b9fba3924	1371	}
frank26080115	0:bf7b9fba3924	1372	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
frank26080115	0:bf7b9fba3924	1373	}
frank26080115	0:bf7b9fba3924	1374	}
frank26080115	0:bf7b9fba3924	1375	}
frank26080115	0:bf7b9fba3924	1376
frank26080115	0:bf7b9fba3924	1377	/* Our response will be a SYNACK. */
frank26080115	0:bf7b9fba3924	1378	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	1379	tcp_send_synack:
frank26080115	0:bf7b9fba3924	1380	BUF->flags = TCP_ACK;
frank26080115	0:bf7b9fba3924	1381
frank26080115	0:bf7b9fba3924	1382	tcp_send_syn:
frank26080115	0:bf7b9fba3924	1383	BUF->flags \|= TCP_SYN;
frank26080115	0:bf7b9fba3924	1384	#else /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	1385	tcp_send_synack:
frank26080115	0:bf7b9fba3924	1386	BUF->flags = TCP_SYN \| TCP_ACK;
frank26080115	0:bf7b9fba3924	1387	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	1388
frank26080115	0:bf7b9fba3924	1389	/* We send out the TCP Maximum Segment Size option with our
frank26080115	0:bf7b9fba3924	1390	SYNACK. */
frank26080115	0:bf7b9fba3924	1391	BUF->optdata[0] = TCP_OPT_MSS;
frank26080115	0:bf7b9fba3924	1392	BUF->optdata[1] = TCP_OPT_MSS_LEN;
frank26080115	0:bf7b9fba3924	1393	BUF->optdata[2] = (UIP_TCP_MSS) / 256;
frank26080115	0:bf7b9fba3924	1394	BUF->optdata[3] = (UIP_TCP_MSS) & 255;
frank26080115	0:bf7b9fba3924	1395	uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
frank26080115	0:bf7b9fba3924	1396	BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
frank26080115	0:bf7b9fba3924	1397	goto tcp_send;
frank26080115	0:bf7b9fba3924	1398
frank26080115	0:bf7b9fba3924	1399	/* This label will be jumped to if we found an active connection. */
frank26080115	0:bf7b9fba3924	1400	found:
frank26080115	0:bf7b9fba3924	1401	uip_conn = uip_connr;
frank26080115	0:bf7b9fba3924	1402	uip_flags = 0;
frank26080115	0:bf7b9fba3924	1403	/* We do a very naive form of TCP reset processing; we just accept
frank26080115	0:bf7b9fba3924	1404	any RST and kill our connection. We should in fact check if the
frank26080115	0:bf7b9fba3924	1405	sequence number of this reset is wihtin our advertised window
frank26080115	0:bf7b9fba3924	1406	before we accept the reset. */
frank26080115	0:bf7b9fba3924	1407	if(BUF->flags & TCP_RST) {
frank26080115	0:bf7b9fba3924	1408	uip_connr->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	1409	UIP_LOG("tcp: got reset, aborting connection.");
frank26080115	0:bf7b9fba3924	1410	uip_flags = UIP_ABORT;
frank26080115	0:bf7b9fba3924	1411	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1412	goto drop;
frank26080115	0:bf7b9fba3924	1413	}
frank26080115	0:bf7b9fba3924	1414	/* Calculated the length of the data, if the application has sent
frank26080115	0:bf7b9fba3924	1415	any data to us. */
frank26080115	0:bf7b9fba3924	1416	c = (BUF->tcpoffset >> 4) << 2;
frank26080115	0:bf7b9fba3924	1417	/* uip_len will contain the length of the actual TCP data. This is
frank26080115	0:bf7b9fba3924	1418	calculated by subtracing the length of the TCP header (in
frank26080115	0:bf7b9fba3924	1419	c) and the length of the IP header (20 bytes). */
frank26080115	0:bf7b9fba3924	1420	uip_len = uip_len - c - UIP_IPH_LEN;
frank26080115	0:bf7b9fba3924	1421
frank26080115	0:bf7b9fba3924	1422	/* First, check if the sequence number of the incoming packet is
frank26080115	0:bf7b9fba3924	1423	what we're expecting next. If not, we send out an ACK with the
frank26080115	0:bf7b9fba3924	1424	correct numbers in. */
frank26080115	0:bf7b9fba3924	1425	if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) &&
frank26080115	0:bf7b9fba3924	1426	((BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK)))) {
frank26080115	0:bf7b9fba3924	1427	if((uip_len > 0 \|\| ((BUF->flags & (TCP_SYN \| TCP_FIN)) != 0)) &&
frank26080115	0:bf7b9fba3924	1428	(BUF->seqno[0] != uip_connr->rcv_nxt[0] \|\|
frank26080115	0:bf7b9fba3924	1429	BUF->seqno[1] != uip_connr->rcv_nxt[1] \|\|
frank26080115	0:bf7b9fba3924	1430	BUF->seqno[2] != uip_connr->rcv_nxt[2] \|\|
frank26080115	0:bf7b9fba3924	1431	BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
frank26080115	0:bf7b9fba3924	1432	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1433	}
frank26080115	0:bf7b9fba3924	1434	}
frank26080115	0:bf7b9fba3924	1435
frank26080115	0:bf7b9fba3924	1436	/* Next, check if the incoming segment acknowledges any outstanding
frank26080115	0:bf7b9fba3924	1437	data. If so, we update the sequence number, reset the length of
frank26080115	0:bf7b9fba3924	1438	the outstanding data, calculate RTT estimations, and reset the
frank26080115	0:bf7b9fba3924	1439	retransmission timer. */
frank26080115	0:bf7b9fba3924	1440	if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
frank26080115	0:bf7b9fba3924	1441	uip_add32(uip_connr->snd_nxt, uip_connr->len);
frank26080115	0:bf7b9fba3924	1442
frank26080115	0:bf7b9fba3924	1443	if(BUF->ackno[0] == uip_acc32[0] &&
frank26080115	0:bf7b9fba3924	1444	BUF->ackno[1] == uip_acc32[1] &&
frank26080115	0:bf7b9fba3924	1445	BUF->ackno[2] == uip_acc32[2] &&
frank26080115	0:bf7b9fba3924	1446	BUF->ackno[3] == uip_acc32[3]) {
frank26080115	0:bf7b9fba3924	1447	/* Update sequence number. */
frank26080115	0:bf7b9fba3924	1448	uip_connr->snd_nxt[0] = uip_acc32[0];
frank26080115	0:bf7b9fba3924	1449	uip_connr->snd_nxt[1] = uip_acc32[1];
frank26080115	0:bf7b9fba3924	1450	uip_connr->snd_nxt[2] = uip_acc32[2];
frank26080115	0:bf7b9fba3924	1451	uip_connr->snd_nxt[3] = uip_acc32[3];
frank26080115	0:bf7b9fba3924	1452
frank26080115	0:bf7b9fba3924	1453
frank26080115	0:bf7b9fba3924	1454	/* Do RTT estimation, unless we have done retransmissions. */
frank26080115	0:bf7b9fba3924	1455	if(uip_connr->nrtx == 0) {
frank26080115	0:bf7b9fba3924	1456	signed char m;
frank26080115	0:bf7b9fba3924	1457	m = uip_connr->rto - uip_connr->timer;
frank26080115	0:bf7b9fba3924	1458	/* This is taken directly from VJs original code in his paper */
frank26080115	0:bf7b9fba3924	1459	m = m - (uip_connr->sa >> 3);
frank26080115	0:bf7b9fba3924	1460	uip_connr->sa += m;
frank26080115	0:bf7b9fba3924	1461	if(m < 0) {
frank26080115	0:bf7b9fba3924	1462	m = -m;
frank26080115	0:bf7b9fba3924	1463	}
frank26080115	0:bf7b9fba3924	1464	m = m - (uip_connr->sv >> 2);
frank26080115	0:bf7b9fba3924	1465	uip_connr->sv += m;
frank26080115	0:bf7b9fba3924	1466	uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
frank26080115	0:bf7b9fba3924	1467
frank26080115	0:bf7b9fba3924	1468	}
frank26080115	0:bf7b9fba3924	1469	/* Set the acknowledged flag. */
frank26080115	0:bf7b9fba3924	1470	uip_flags = UIP_ACKDATA;
frank26080115	0:bf7b9fba3924	1471	/* Reset the retransmission timer. */
frank26080115	0:bf7b9fba3924	1472	uip_connr->timer = uip_connr->rto;
frank26080115	0:bf7b9fba3924	1473
frank26080115	0:bf7b9fba3924	1474	/* Reset length of outstanding data. */
frank26080115	0:bf7b9fba3924	1475	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1476	}
frank26080115	0:bf7b9fba3924	1477
frank26080115	0:bf7b9fba3924	1478	}
frank26080115	0:bf7b9fba3924	1479
frank26080115	0:bf7b9fba3924	1480	/* Do different things depending on in what state the connection is. */
frank26080115	0:bf7b9fba3924	1481	switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
frank26080115	0:bf7b9fba3924	1482	/* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
frank26080115	0:bf7b9fba3924	1483	implemented, since we force the application to close when the
frank26080115	0:bf7b9fba3924	1484	peer sends a FIN (hence the application goes directly from
frank26080115	0:bf7b9fba3924	1485	ESTABLISHED to LAST_ACK). */
frank26080115	0:bf7b9fba3924	1486	case UIP_SYN_RCVD:
frank26080115	0:bf7b9fba3924	1487	/* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
frank26080115	0:bf7b9fba3924	1488	we are waiting for an ACK that acknowledges the data we sent
frank26080115	0:bf7b9fba3924	1489	out the last time. Therefore, we want to have the UIP_ACKDATA
frank26080115	0:bf7b9fba3924	1490	flag set. If so, we enter the ESTABLISHED state. */
frank26080115	0:bf7b9fba3924	1491	if(uip_flags & UIP_ACKDATA) {
frank26080115	0:bf7b9fba3924	1492	uip_connr->tcpstateflags = UIP_ESTABLISHED;
frank26080115	0:bf7b9fba3924	1493	uip_flags = UIP_CONNECTED;
frank26080115	0:bf7b9fba3924	1494	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1495	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1496	uip_flags \|= UIP_NEWDATA;
frank26080115	0:bf7b9fba3924	1497	uip_add_rcv_nxt(uip_len);
frank26080115	0:bf7b9fba3924	1498	}
frank26080115	0:bf7b9fba3924	1499	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1500	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1501	goto appsend;
frank26080115	0:bf7b9fba3924	1502	}
frank26080115	0:bf7b9fba3924	1503	goto drop;
frank26080115	0:bf7b9fba3924	1504	#if UIP_ACTIVE_OPEN
frank26080115	0:bf7b9fba3924	1505	case UIP_SYN_SENT:
frank26080115	0:bf7b9fba3924	1506	/* In SYN_SENT, we wait for a SYNACK that is sent in response to
frank26080115	0:bf7b9fba3924	1507	our SYN. The rcv_nxt is set to sequence number in the SYNACK
frank26080115	0:bf7b9fba3924	1508	plus one, and we send an ACK. We move into the ESTABLISHED
frank26080115	0:bf7b9fba3924	1509	state. */
frank26080115	0:bf7b9fba3924	1510	if((uip_flags & UIP_ACKDATA) &&
frank26080115	0:bf7b9fba3924	1511	(BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK)) {
frank26080115	0:bf7b9fba3924	1512
frank26080115	0:bf7b9fba3924	1513	/* Parse the TCP MSS option, if present. */
frank26080115	0:bf7b9fba3924	1514	if((BUF->tcpoffset & 0xf0) > 0x50) {
frank26080115	0:bf7b9fba3924	1515	for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
frank26080115	0:bf7b9fba3924	1516	opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
frank26080115	0:bf7b9fba3924	1517	if(opt == TCP_OPT_END) {
frank26080115	0:bf7b9fba3924	1518	/* End of options. */
frank26080115	0:bf7b9fba3924	1519	break;
frank26080115	0:bf7b9fba3924	1520	} else if(opt == TCP_OPT_NOOP) {
frank26080115	0:bf7b9fba3924	1521	++c;
frank26080115	0:bf7b9fba3924	1522	/* NOP option. */
frank26080115	0:bf7b9fba3924	1523	} else if(opt == TCP_OPT_MSS &&
frank26080115	0:bf7b9fba3924	1524	uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
frank26080115	0:bf7b9fba3924	1525	/* An MSS option with the right option length. */
frank26080115	0:bf7b9fba3924	1526	tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) \|
frank26080115	0:bf7b9fba3924	1527	uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
frank26080115	0:bf7b9fba3924	1528	uip_connr->initialmss =
frank26080115	0:bf7b9fba3924	1529	uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
frank26080115	0:bf7b9fba3924	1530
frank26080115	0:bf7b9fba3924	1531	/* And we are done processing options. */
frank26080115	0:bf7b9fba3924	1532	break;
frank26080115	0:bf7b9fba3924	1533	} else {
frank26080115	0:bf7b9fba3924	1534	/* All other options have a length field, so that we easily
frank26080115	0:bf7b9fba3924	1535	can skip past them. */
frank26080115	0:bf7b9fba3924	1536	if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
frank26080115	0:bf7b9fba3924	1537	/* If the length field is zero, the options are malformed
frank26080115	0:bf7b9fba3924	1538	and we don't process them further. */
frank26080115	0:bf7b9fba3924	1539	break;
frank26080115	0:bf7b9fba3924	1540	}
frank26080115	0:bf7b9fba3924	1541	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
frank26080115	0:bf7b9fba3924	1542	}
frank26080115	0:bf7b9fba3924	1543	}
frank26080115	0:bf7b9fba3924	1544	}
frank26080115	0:bf7b9fba3924	1545	uip_connr->tcpstateflags = UIP_ESTABLISHED;
frank26080115	0:bf7b9fba3924	1546	uip_connr->rcv_nxt[0] = BUF->seqno[0];
frank26080115	0:bf7b9fba3924	1547	uip_connr->rcv_nxt[1] = BUF->seqno[1];
frank26080115	0:bf7b9fba3924	1548	uip_connr->rcv_nxt[2] = BUF->seqno[2];
frank26080115	0:bf7b9fba3924	1549	uip_connr->rcv_nxt[3] = BUF->seqno[3];
frank26080115	0:bf7b9fba3924	1550	uip_add_rcv_nxt(1);
frank26080115	0:bf7b9fba3924	1551	uip_flags = UIP_CONNECTED \| UIP_NEWDATA;
frank26080115	0:bf7b9fba3924	1552	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1553	uip_len = 0;
frank26080115	0:bf7b9fba3924	1554	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1555	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1556	goto appsend;
frank26080115	0:bf7b9fba3924	1557	}
frank26080115	0:bf7b9fba3924	1558	/* Inform the application that the connection failed */
frank26080115	0:bf7b9fba3924	1559	uip_flags = UIP_ABORT;
frank26080115	0:bf7b9fba3924	1560	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1561	/* The connection is closed after we send the RST */
frank26080115	0:bf7b9fba3924	1562	uip_conn->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	1563	goto reset;
frank26080115	0:bf7b9fba3924	1564	#endif /* UIP_ACTIVE_OPEN */
frank26080115	0:bf7b9fba3924	1565
frank26080115	0:bf7b9fba3924	1566	case UIP_ESTABLISHED:
frank26080115	0:bf7b9fba3924	1567	/* In the ESTABLISHED state, we call upon the application to feed
frank26080115	0:bf7b9fba3924	1568	data into the uip_buf. If the UIP_ACKDATA flag is set, the
frank26080115	0:bf7b9fba3924	1569	application should put new data into the buffer, otherwise we are
frank26080115	0:bf7b9fba3924	1570	retransmitting an old segment, and the application should put that
frank26080115	0:bf7b9fba3924	1571	data into the buffer.
frank26080115	0:bf7b9fba3924	1572
frank26080115	0:bf7b9fba3924	1573	If the incoming packet is a FIN, we should close the connection on
frank26080115	0:bf7b9fba3924	1574	this side as well, and we send out a FIN and enter the LAST_ACK
frank26080115	0:bf7b9fba3924	1575	state. We require that there is no outstanding data; otherwise the
frank26080115	0:bf7b9fba3924	1576	sequence numbers will be screwed up. */
frank26080115	0:bf7b9fba3924	1577
frank26080115	0:bf7b9fba3924	1578	if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
frank26080115	0:bf7b9fba3924	1579	if(uip_outstanding(uip_connr)) {
frank26080115	0:bf7b9fba3924	1580	goto drop;
frank26080115	0:bf7b9fba3924	1581	}
frank26080115	0:bf7b9fba3924	1582	uip_add_rcv_nxt(1 + uip_len);
frank26080115	0:bf7b9fba3924	1583	uip_flags \|= UIP_CLOSE;
frank26080115	0:bf7b9fba3924	1584	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1585	uip_flags \|= UIP_NEWDATA;
frank26080115	0:bf7b9fba3924	1586	}
frank26080115	0:bf7b9fba3924	1587	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1588	uip_connr->len = 1;
frank26080115	0:bf7b9fba3924	1589	uip_connr->tcpstateflags = UIP_LAST_ACK;
frank26080115	0:bf7b9fba3924	1590	uip_connr->nrtx = 0;
frank26080115	0:bf7b9fba3924	1591	tcp_send_finack:
frank26080115	0:bf7b9fba3924	1592	BUF->flags = TCP_FIN \| TCP_ACK;
frank26080115	0:bf7b9fba3924	1593	goto tcp_send_nodata;
frank26080115	0:bf7b9fba3924	1594	}
frank26080115	0:bf7b9fba3924	1595
frank26080115	0:bf7b9fba3924	1596	/* Check the URG flag. If this is set, the segment carries urgent
frank26080115	0:bf7b9fba3924	1597	data that we must pass to the application. */
frank26080115	0:bf7b9fba3924	1598	if((BUF->flags & TCP_URG) != 0) {
frank26080115	0:bf7b9fba3924	1599	#if UIP_URGDATA > 0
frank26080115	0:bf7b9fba3924	1600	uip_urglen = (BUF->urgp[0] << 8) \| BUF->urgp[1];
frank26080115	0:bf7b9fba3924	1601	if(uip_urglen > uip_len) {
frank26080115	0:bf7b9fba3924	1602	/* There is more urgent data in the next segment to come. */
frank26080115	0:bf7b9fba3924	1603	uip_urglen = uip_len;
frank26080115	0:bf7b9fba3924	1604	}
frank26080115	0:bf7b9fba3924	1605	uip_add_rcv_nxt(uip_urglen);
frank26080115	0:bf7b9fba3924	1606	uip_len -= uip_urglen;
frank26080115	0:bf7b9fba3924	1607	uip_urgdata = uip_appdata;
frank26080115	0:bf7b9fba3924	1608	uip_appdata += uip_urglen;
frank26080115	0:bf7b9fba3924	1609	} else {
frank26080115	0:bf7b9fba3924	1610	uip_urglen = 0;
frank26080115	0:bf7b9fba3924	1611	#else /* UIP_URGDATA > 0 */
frank26080115	0:bf7b9fba3924	1612	uip_appdata = ((char *)uip_appdata) + ((BUF->urgp[0] << 8) \| BUF->urgp[1]);
frank26080115	0:bf7b9fba3924	1613	uip_len -= (BUF->urgp[0] << 8) \| BUF->urgp[1];
frank26080115	0:bf7b9fba3924	1614	#endif /* UIP_URGDATA > 0 */
frank26080115	0:bf7b9fba3924	1615	}
frank26080115	0:bf7b9fba3924	1616
frank26080115	0:bf7b9fba3924	1617	/* If uip_len > 0 we have TCP data in the packet, and we flag this
frank26080115	0:bf7b9fba3924	1618	by setting the UIP_NEWDATA flag and update the sequence number
frank26080115	0:bf7b9fba3924	1619	we acknowledge. If the application has stopped the dataflow
frank26080115	0:bf7b9fba3924	1620	using uip_stop(), we must not accept any data packets from the
frank26080115	0:bf7b9fba3924	1621	remote host. */
frank26080115	0:bf7b9fba3924	1622	if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
frank26080115	0:bf7b9fba3924	1623	uip_flags \|= UIP_NEWDATA;
frank26080115	0:bf7b9fba3924	1624	uip_add_rcv_nxt(uip_len);
frank26080115	0:bf7b9fba3924	1625	}
frank26080115	0:bf7b9fba3924	1626
frank26080115	0:bf7b9fba3924	1627	/* Check if the available buffer space advertised by the other end
frank26080115	0:bf7b9fba3924	1628	is smaller than the initial MSS for this connection. If so, we
frank26080115	0:bf7b9fba3924	1629	set the current MSS to the window size to ensure that the
frank26080115	0:bf7b9fba3924	1630	application does not send more data than the other end can
frank26080115	0:bf7b9fba3924	1631	handle.
frank26080115	0:bf7b9fba3924	1632
frank26080115	0:bf7b9fba3924	1633	If the remote host advertises a zero window, we set the MSS to
frank26080115	0:bf7b9fba3924	1634	the initial MSS so that the application will send an entire MSS
frank26080115	0:bf7b9fba3924	1635	of data. This data will not be acknowledged by the receiver,
frank26080115	0:bf7b9fba3924	1636	and the application will retransmit it. This is called the
frank26080115	0:bf7b9fba3924	1637	"persistent timer" and uses the retransmission mechanim.
frank26080115	0:bf7b9fba3924	1638	*/
frank26080115	0:bf7b9fba3924	1639	tmp16 = ((u16_t)BUF->wnd[0] << 8) + (u16_t)BUF->wnd[1];
frank26080115	0:bf7b9fba3924	1640	if(tmp16 > uip_connr->initialmss \|\|
frank26080115	0:bf7b9fba3924	1641	tmp16 == 0) {
frank26080115	0:bf7b9fba3924	1642	tmp16 = uip_connr->initialmss;
frank26080115	0:bf7b9fba3924	1643	}
frank26080115	0:bf7b9fba3924	1644	uip_connr->mss = tmp16;
frank26080115	0:bf7b9fba3924	1645
frank26080115	0:bf7b9fba3924	1646	/* If this packet constitutes an ACK for outstanding data (flagged
frank26080115	0:bf7b9fba3924	1647	by the UIP_ACKDATA flag, we should call the application since it
frank26080115	0:bf7b9fba3924	1648	might want to send more data. If the incoming packet had data
frank26080115	0:bf7b9fba3924	1649	from the peer (as flagged by the UIP_NEWDATA flag), the
frank26080115	0:bf7b9fba3924	1650	application must also be notified.
frank26080115	0:bf7b9fba3924	1651
frank26080115	0:bf7b9fba3924	1652	When the application is called, the global variable uip_len
frank26080115	0:bf7b9fba3924	1653	contains the length of the incoming data. The application can
frank26080115	0:bf7b9fba3924	1654	access the incoming data through the global pointer
frank26080115	0:bf7b9fba3924	1655	uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
frank26080115	0:bf7b9fba3924	1656	bytes into the uip_buf array.
frank26080115	0:bf7b9fba3924	1657
frank26080115	0:bf7b9fba3924	1658	If the application wishes to send any data, this data should be
frank26080115	0:bf7b9fba3924	1659	put into the uip_appdata and the length of the data should be
frank26080115	0:bf7b9fba3924	1660	put into uip_len. If the application don't have any data to
frank26080115	0:bf7b9fba3924	1661	send, uip_len must be set to 0. */
frank26080115	0:bf7b9fba3924	1662	if(uip_flags & (UIP_NEWDATA \| UIP_ACKDATA)) {
frank26080115	0:bf7b9fba3924	1663	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1664	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1665
frank26080115	0:bf7b9fba3924	1666	appsend:
frank26080115	0:bf7b9fba3924	1667
frank26080115	0:bf7b9fba3924	1668	if(uip_flags & UIP_ABORT) {
frank26080115	0:bf7b9fba3924	1669	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1670	uip_connr->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	1671	BUF->flags = TCP_RST \| TCP_ACK;
frank26080115	0:bf7b9fba3924	1672	goto tcp_send_nodata;
frank26080115	0:bf7b9fba3924	1673	}
frank26080115	0:bf7b9fba3924	1674
frank26080115	0:bf7b9fba3924	1675	if(uip_flags & UIP_CLOSE) {
frank26080115	0:bf7b9fba3924	1676	uip_slen = 0;
frank26080115	0:bf7b9fba3924	1677	uip_connr->len = 1;
frank26080115	0:bf7b9fba3924	1678	uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
frank26080115	0:bf7b9fba3924	1679	uip_connr->nrtx = 0;
frank26080115	0:bf7b9fba3924	1680	BUF->flags = TCP_FIN \| TCP_ACK;
frank26080115	0:bf7b9fba3924	1681	goto tcp_send_nodata;
frank26080115	0:bf7b9fba3924	1682	}
frank26080115	0:bf7b9fba3924	1683
frank26080115	0:bf7b9fba3924	1684	/* If uip_slen > 0, the application has data to be sent. */
frank26080115	0:bf7b9fba3924	1685	if(uip_slen > 0) {
frank26080115	0:bf7b9fba3924	1686
frank26080115	0:bf7b9fba3924	1687	/* If the connection has acknowledged data, the contents of
frank26080115	0:bf7b9fba3924	1688	the ->len variable should be discarded. */
frank26080115	0:bf7b9fba3924	1689	if((uip_flags & UIP_ACKDATA) != 0) {
frank26080115	0:bf7b9fba3924	1690	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1691	}
frank26080115	0:bf7b9fba3924	1692
frank26080115	0:bf7b9fba3924	1693	/* If the ->len variable is non-zero the connection has
frank26080115	0:bf7b9fba3924	1694	already data in transit and cannot send anymore right
frank26080115	0:bf7b9fba3924	1695	now. */
frank26080115	0:bf7b9fba3924	1696	if(uip_connr->len == 0) {
frank26080115	0:bf7b9fba3924	1697
frank26080115	0:bf7b9fba3924	1698	/* The application cannot send more than what is allowed by
frank26080115	0:bf7b9fba3924	1699	the mss (the minumum of the MSS and the available
frank26080115	0:bf7b9fba3924	1700	window). */
frank26080115	0:bf7b9fba3924	1701	if(uip_slen > uip_connr->mss) {
frank26080115	0:bf7b9fba3924	1702	uip_slen = uip_connr->mss;
frank26080115	0:bf7b9fba3924	1703	}
frank26080115	0:bf7b9fba3924	1704
frank26080115	0:bf7b9fba3924	1705	/* Remember how much data we send out now so that we know
frank26080115	0:bf7b9fba3924	1706	when everything has been acknowledged. */
frank26080115	0:bf7b9fba3924	1707	uip_connr->len = uip_slen;
frank26080115	0:bf7b9fba3924	1708	} else {
frank26080115	0:bf7b9fba3924	1709
frank26080115	0:bf7b9fba3924	1710	/* If the application already had unacknowledged data, we
frank26080115	0:bf7b9fba3924	1711	make sure that the application does not send (i.e.,
frank26080115	0:bf7b9fba3924	1712	retransmit) out more than it previously sent out. */
frank26080115	0:bf7b9fba3924	1713	uip_slen = uip_connr->len;
frank26080115	0:bf7b9fba3924	1714	}
frank26080115	0:bf7b9fba3924	1715	}
frank26080115	0:bf7b9fba3924	1716	uip_connr->nrtx = 0;
frank26080115	0:bf7b9fba3924	1717	apprexmit:
frank26080115	0:bf7b9fba3924	1718	uip_appdata = uip_sappdata;
frank26080115	0:bf7b9fba3924	1719
frank26080115	0:bf7b9fba3924	1720	/* If the application has data to be sent, or if the incoming
frank26080115	0:bf7b9fba3924	1721	packet had new data in it, we must send out a packet. */
frank26080115	0:bf7b9fba3924	1722	if(uip_slen > 0 && uip_connr->len > 0) {
frank26080115	0:bf7b9fba3924	1723	/* Add the length of the IP and TCP headers. */
frank26080115	0:bf7b9fba3924	1724	uip_len = uip_connr->len + UIP_TCPIP_HLEN;
frank26080115	0:bf7b9fba3924	1725	/* We always set the ACK flag in response packets. */
frank26080115	0:bf7b9fba3924	1726	BUF->flags = TCP_ACK \| TCP_PSH;
frank26080115	0:bf7b9fba3924	1727	/* Send the packet. */
frank26080115	0:bf7b9fba3924	1728	goto tcp_send_noopts;
frank26080115	0:bf7b9fba3924	1729	}
frank26080115	0:bf7b9fba3924	1730	/* If there is no data to send, just send out a pure ACK if
frank26080115	0:bf7b9fba3924	1731	there is newdata. */
frank26080115	0:bf7b9fba3924	1732	if(uip_flags & UIP_NEWDATA) {
frank26080115	0:bf7b9fba3924	1733	uip_len = UIP_TCPIP_HLEN;
frank26080115	0:bf7b9fba3924	1734	BUF->flags = TCP_ACK;
frank26080115	0:bf7b9fba3924	1735	goto tcp_send_noopts;
frank26080115	0:bf7b9fba3924	1736	}
frank26080115	0:bf7b9fba3924	1737	}
frank26080115	0:bf7b9fba3924	1738	goto drop;
frank26080115	0:bf7b9fba3924	1739	case UIP_LAST_ACK:
frank26080115	0:bf7b9fba3924	1740	/* We can close this connection if the peer has acknowledged our
frank26080115	0:bf7b9fba3924	1741	FIN. This is indicated by the UIP_ACKDATA flag. */
frank26080115	0:bf7b9fba3924	1742	if(uip_flags & UIP_ACKDATA) {
frank26080115	0:bf7b9fba3924	1743	uip_connr->tcpstateflags = UIP_CLOSED;
frank26080115	0:bf7b9fba3924	1744	uip_flags = UIP_CLOSE;
frank26080115	0:bf7b9fba3924	1745	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1746	}
frank26080115	0:bf7b9fba3924	1747	break;
frank26080115	0:bf7b9fba3924	1748
frank26080115	0:bf7b9fba3924	1749	case UIP_FIN_WAIT_1:
frank26080115	0:bf7b9fba3924	1750	/* The application has closed the connection, but the remote host
frank26080115	0:bf7b9fba3924	1751	hasn't closed its end yet. Thus we do nothing but wait for a
frank26080115	0:bf7b9fba3924	1752	FIN from the other side. */
frank26080115	0:bf7b9fba3924	1753	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1754	uip_add_rcv_nxt(uip_len);
frank26080115	0:bf7b9fba3924	1755	}
frank26080115	0:bf7b9fba3924	1756	if(BUF->flags & TCP_FIN) {
frank26080115	0:bf7b9fba3924	1757	if(uip_flags & UIP_ACKDATA) {
frank26080115	0:bf7b9fba3924	1758	uip_connr->tcpstateflags = UIP_TIME_WAIT;
frank26080115	0:bf7b9fba3924	1759	uip_connr->timer = 0;
frank26080115	0:bf7b9fba3924	1760	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1761	} else {
frank26080115	0:bf7b9fba3924	1762	uip_connr->tcpstateflags = UIP_CLOSING;
frank26080115	0:bf7b9fba3924	1763	}
frank26080115	0:bf7b9fba3924	1764	uip_add_rcv_nxt(1);
frank26080115	0:bf7b9fba3924	1765	uip_flags = UIP_CLOSE;
frank26080115	0:bf7b9fba3924	1766	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1767	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1768	} else if(uip_flags & UIP_ACKDATA) {
frank26080115	0:bf7b9fba3924	1769	uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
frank26080115	0:bf7b9fba3924	1770	uip_connr->len = 0;
frank26080115	0:bf7b9fba3924	1771	goto drop;
frank26080115	0:bf7b9fba3924	1772	}
frank26080115	0:bf7b9fba3924	1773	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1774	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1775	}
frank26080115	0:bf7b9fba3924	1776	goto drop;
frank26080115	0:bf7b9fba3924	1777
frank26080115	0:bf7b9fba3924	1778	case UIP_FIN_WAIT_2:
frank26080115	0:bf7b9fba3924	1779	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1780	uip_add_rcv_nxt(uip_len);
frank26080115	0:bf7b9fba3924	1781	}
frank26080115	0:bf7b9fba3924	1782	if(BUF->flags & TCP_FIN) {
frank26080115	0:bf7b9fba3924	1783	uip_connr->tcpstateflags = UIP_TIME_WAIT;
frank26080115	0:bf7b9fba3924	1784	uip_connr->timer = 0;
frank26080115	0:bf7b9fba3924	1785	uip_add_rcv_nxt(1);
frank26080115	0:bf7b9fba3924	1786	uip_flags = UIP_CLOSE;
frank26080115	0:bf7b9fba3924	1787	UIP_APPCALL();
frank26080115	0:bf7b9fba3924	1788	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1789	}
frank26080115	0:bf7b9fba3924	1790	if(uip_len > 0) {
frank26080115	0:bf7b9fba3924	1791	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1792	}
frank26080115	0:bf7b9fba3924	1793	goto drop;
frank26080115	0:bf7b9fba3924	1794
frank26080115	0:bf7b9fba3924	1795	case UIP_TIME_WAIT:
frank26080115	0:bf7b9fba3924	1796	goto tcp_send_ack;
frank26080115	0:bf7b9fba3924	1797
frank26080115	0:bf7b9fba3924	1798	case UIP_CLOSING:
frank26080115	0:bf7b9fba3924	1799	if(uip_flags & UIP_ACKDATA) {
frank26080115	0:bf7b9fba3924	1800	uip_connr->tcpstateflags = UIP_TIME_WAIT;
frank26080115	0:bf7b9fba3924	1801	uip_connr->timer = 0;
frank26080115	0:bf7b9fba3924	1802	}
frank26080115	0:bf7b9fba3924	1803	}
frank26080115	0:bf7b9fba3924	1804	goto drop;
frank26080115	0:bf7b9fba3924	1805
frank26080115	0:bf7b9fba3924	1806
frank26080115	0:bf7b9fba3924	1807	/* We jump here when we are ready to send the packet, and just want
frank26080115	0:bf7b9fba3924	1808	to set the appropriate TCP sequence numbers in the TCP header. */
frank26080115	0:bf7b9fba3924	1809	tcp_send_ack:
frank26080115	0:bf7b9fba3924	1810	BUF->flags = TCP_ACK;
frank26080115	0:bf7b9fba3924	1811	tcp_send_nodata:
frank26080115	0:bf7b9fba3924	1812	uip_len = UIP_IPTCPH_LEN;
frank26080115	0:bf7b9fba3924	1813	tcp_send_noopts:
frank26080115	0:bf7b9fba3924	1814	BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
frank26080115	0:bf7b9fba3924	1815	tcp_send:
frank26080115	0:bf7b9fba3924	1816	/* We're done with the input processing. We are now ready to send a
frank26080115	0:bf7b9fba3924	1817	reply. Our job is to fill in all the fields of the TCP and IP
frank26080115	0:bf7b9fba3924	1818	headers before calculating the checksum and finally send the
frank26080115	0:bf7b9fba3924	1819	packet. */
frank26080115	0:bf7b9fba3924	1820	BUF->ackno[0] = uip_connr->rcv_nxt[0];
frank26080115	0:bf7b9fba3924	1821	BUF->ackno[1] = uip_connr->rcv_nxt[1];
frank26080115	0:bf7b9fba3924	1822	BUF->ackno[2] = uip_connr->rcv_nxt[2];
frank26080115	0:bf7b9fba3924	1823	BUF->ackno[3] = uip_connr->rcv_nxt[3];
frank26080115	0:bf7b9fba3924	1824
frank26080115	0:bf7b9fba3924	1825	BUF->seqno[0] = uip_connr->snd_nxt[0];
frank26080115	0:bf7b9fba3924	1826	BUF->seqno[1] = uip_connr->snd_nxt[1];
frank26080115	0:bf7b9fba3924	1827	BUF->seqno[2] = uip_connr->snd_nxt[2];
frank26080115	0:bf7b9fba3924	1828	BUF->seqno[3] = uip_connr->snd_nxt[3];
frank26080115	0:bf7b9fba3924	1829
frank26080115	0:bf7b9fba3924	1830	BUF->proto = UIP_PROTO_TCP;
frank26080115	0:bf7b9fba3924	1831
frank26080115	0:bf7b9fba3924	1832	BUF->srcport = uip_connr->lport;
frank26080115	0:bf7b9fba3924	1833	BUF->destport = uip_connr->rport;
frank26080115	0:bf7b9fba3924	1834
frank26080115	0:bf7b9fba3924	1835	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
frank26080115	0:bf7b9fba3924	1836	uip_ipaddr_copy(BUF->destipaddr, uip_connr->ripaddr);
frank26080115	0:bf7b9fba3924	1837
frank26080115	0:bf7b9fba3924	1838	if(uip_connr->tcpstateflags & UIP_STOPPED) {
frank26080115	0:bf7b9fba3924	1839	/* If the connection has issued uip_stop(), we advertise a zero
frank26080115	0:bf7b9fba3924	1840	window so that the remote host will stop sending data. */
frank26080115	0:bf7b9fba3924	1841	BUF->wnd[0] = BUF->wnd[1] = 0;
frank26080115	0:bf7b9fba3924	1842	} else {
frank26080115	0:bf7b9fba3924	1843	BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
frank26080115	0:bf7b9fba3924	1844	BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
frank26080115	0:bf7b9fba3924	1845	}
frank26080115	0:bf7b9fba3924	1846
frank26080115	0:bf7b9fba3924	1847	tcp_send_noconn:
frank26080115	0:bf7b9fba3924	1848	BUF->ttl = UIP_TTL;
frank26080115	0:bf7b9fba3924	1849	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	1850	/* For IPv6, the IP length field does not include the IPv6 IP header
frank26080115	0:bf7b9fba3924	1851	length. */
frank26080115	0:bf7b9fba3924	1852	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
frank26080115	0:bf7b9fba3924	1853	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
frank26080115	0:bf7b9fba3924	1854	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1855	BUF->len[0] = (uip_len >> 8);
frank26080115	0:bf7b9fba3924	1856	BUF->len[1] = (uip_len & 0xff);
frank26080115	0:bf7b9fba3924	1857	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1858
frank26080115	0:bf7b9fba3924	1859	BUF->urgp[0] = BUF->urgp[1] = 0;
frank26080115	0:bf7b9fba3924	1860
frank26080115	0:bf7b9fba3924	1861	/* Calculate TCP checksum. */
frank26080115	0:bf7b9fba3924	1862	BUF->tcpchksum = 0;
frank26080115	0:bf7b9fba3924	1863	BUF->tcpchksum = ~(uip_tcpchksum());
frank26080115	0:bf7b9fba3924	1864
frank26080115	0:bf7b9fba3924	1865	#if UIP_UDP
frank26080115	0:bf7b9fba3924	1866	ip_send_nolen:
frank26080115	0:bf7b9fba3924	1867	#endif /* UIP_UDP */
frank26080115	0:bf7b9fba3924	1868
frank26080115	0:bf7b9fba3924	1869	#if UIP_CONF_IPV6
frank26080115	0:bf7b9fba3924	1870	BUF->vtc = 0x60;
frank26080115	0:bf7b9fba3924	1871	BUF->tcflow = 0x00;
frank26080115	0:bf7b9fba3924	1872	BUF->flow = 0x00;
frank26080115	0:bf7b9fba3924	1873	#else /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1874	BUF->vhl = 0x45;
frank26080115	0:bf7b9fba3924	1875	BUF->tos = 0;
frank26080115	0:bf7b9fba3924	1876	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
frank26080115	0:bf7b9fba3924	1877	++ipid;
frank26080115	0:bf7b9fba3924	1878	BUF->ipid[0] = ipid >> 8;
frank26080115	0:bf7b9fba3924	1879	BUF->ipid[1] = ipid & 0xff;
frank26080115	0:bf7b9fba3924	1880	/* Calculate IP checksum. */
frank26080115	0:bf7b9fba3924	1881	BUF->ipchksum = 0;
frank26080115	0:bf7b9fba3924	1882	BUF->ipchksum = ~(uip_ipchksum());
frank26080115	0:bf7b9fba3924	1883	DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum());
frank26080115	0:bf7b9fba3924	1884	#endif /* UIP_CONF_IPV6 */
frank26080115	0:bf7b9fba3924	1885
frank26080115	0:bf7b9fba3924	1886	UIP_STAT(++uip_stat.tcp.sent);
frank26080115	0:bf7b9fba3924	1887	send:
frank26080115	0:bf7b9fba3924	1888	DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len,
frank26080115	0:bf7b9fba3924	1889	(BUF->len[0] << 8) \| BUF->len[1]);
frank26080115	0:bf7b9fba3924	1890
frank26080115	0:bf7b9fba3924	1891	UIP_STAT(++uip_stat.ip.sent);
frank26080115	0:bf7b9fba3924	1892	/* Return and let the caller do the actual transmission. */
frank26080115	0:bf7b9fba3924	1893	uip_flags = 0;
frank26080115	0:bf7b9fba3924	1894	return;
frank26080115	0:bf7b9fba3924	1895	drop:
frank26080115	0:bf7b9fba3924	1896	uip_len = 0;
frank26080115	0:bf7b9fba3924	1897	uip_flags = 0;
frank26080115	0:bf7b9fba3924	1898	return;
frank26080115	0:bf7b9fba3924	1899	}
frank26080115	0:bf7b9fba3924	1900	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	1901	u16_t
frank26080115	0:bf7b9fba3924	1902	htons(u16_t val)
frank26080115	0:bf7b9fba3924	1903	{
frank26080115	0:bf7b9fba3924	1904	return HTONS(val);
frank26080115	0:bf7b9fba3924	1905	}
frank26080115	0:bf7b9fba3924	1906	/---------------------------------------------------------------------------/
frank26080115	0:bf7b9fba3924	1907	void
frank26080115	0:bf7b9fba3924	1908	uip_send(const void *data, int len)
frank26080115	0:bf7b9fba3924	1909	{
frank26080115	0:bf7b9fba3924	1910	if(len > 0) {
frank26080115	0:bf7b9fba3924	1911	uip_slen = len;
frank26080115	0:bf7b9fba3924	1912	if(data != uip_sappdata) {
frank26080115	0:bf7b9fba3924	1913	memcpy(uip_sappdata, (data), uip_slen);
frank26080115	0:bf7b9fba3924	1914	}
frank26080115	0:bf7b9fba3924	1915	}
frank26080115	0:bf7b9fba3924	1916	}
frank26080115	0:bf7b9fba3924	1917	/** @} */
frank26080115	0:bf7b9fba3924	1918	/** @} */

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Type:	Program
Created:	20 Mar 2011
Imports:	199
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	7

EMAC/uIP/uip/uip.c@0:bf7b9fba3924, 2011-03-20 (annotated)

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